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Type | Label | Description |
---|---|---|
Statement | ||
Theorem | efcn 24001 | The exponential function is continuous. (Contributed by Paul Chapman, 15-Sep-2007.) (Revised by Mario Carneiro, 20-Jun-2015.) |
⊢ exp ∈ (ℂ–cn→ℂ) | ||
Theorem | sincn 24002 | Sine is continuous. (Contributed by Paul Chapman, 28-Nov-2007.) (Revised by Mario Carneiro, 3-Sep-2014.) |
⊢ sin ∈ (ℂ–cn→ℂ) | ||
Theorem | coscn 24003 | Cosine is continuous. (Contributed by Paul Chapman, 28-Nov-2007.) (Revised by Mario Carneiro, 3-Sep-2014.) |
⊢ cos ∈ (ℂ–cn→ℂ) | ||
Theorem | reeff1olem 24004* | Lemma for reeff1o 24005. (Contributed by Paul Chapman, 18-Oct-2007.) (Revised by Mario Carneiro, 30-Apr-2014.) |
⊢ ((𝑈 ∈ ℝ ∧ 1 < 𝑈) → ∃𝑥 ∈ ℝ (exp‘𝑥) = 𝑈) | ||
Theorem | reeff1o 24005 | The real exponential function is one-to-one onto. (Contributed by Paul Chapman, 18-Oct-2007.) (Revised by Mario Carneiro, 10-Nov-2013.) |
⊢ (exp ↾ ℝ):ℝ–1-1-onto→ℝ+ | ||
Theorem | reefiso 24006 | The exponential function on the reals determines an isomorphism from reals onto positive reals. (Contributed by Steve Rodriguez, 25-Nov-2007.) (Revised by Mario Carneiro, 11-Mar-2014.) |
⊢ (exp ↾ ℝ) Isom < , < (ℝ, ℝ+) | ||
Theorem | efcvx 24007 | The exponential function on the reals is a strictly convex function. (Contributed by Mario Carneiro, 20-Jun-2015.) |
⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐴 < 𝐵) ∧ 𝑇 ∈ (0(,)1)) → (exp‘((𝑇 · 𝐴) + ((1 − 𝑇) · 𝐵))) < ((𝑇 · (exp‘𝐴)) + ((1 − 𝑇) · (exp‘𝐵)))) | ||
Theorem | reefgim 24008 | The exponential function is a group isomorphism from the group of reals under addition to the group of positive reals under multiplication. (Contributed by Mario Carneiro, 21-Jun-2015.) (Revised by Thierry Arnoux, 30-Jun-2019.) |
⊢ 𝑃 = ((mulGrp‘ℂfld) ↾s ℝ+) ⇒ ⊢ (exp ↾ ℝ) ∈ (ℝfld GrpIso 𝑃) | ||
Theorem | pilem1 24009 | Lemma for pire 24014, pigt2lt4 24012 and sinpi 24013. (Contributed by Mario Carneiro, 9-May-2014.) |
⊢ (𝐴 ∈ (ℝ+ ∩ (◡sin “ {0})) ↔ (𝐴 ∈ ℝ+ ∧ (sin‘𝐴) = 0)) | ||
Theorem | pilem2 24010 | Lemma for pire 24014, pigt2lt4 24012 and sinpi 24013. (Contributed by Mario Carneiro, 12-Jun-2014.) (Revised by AV, 14-Sep-2020.) |
⊢ (𝜑 → 𝐴 ∈ (2(,)4)) & ⊢ (𝜑 → 𝐵 ∈ ℝ+) & ⊢ (𝜑 → (sin‘𝐴) = 0) & ⊢ (𝜑 → (sin‘𝐵) = 0) & ⊢ (𝜑 → π < 𝐴) ⇒ ⊢ (𝜑 → ((π + 𝐴) / 2) ≤ 𝐵) | ||
Theorem | pilem3 24011 | Lemma for pire 24014, pigt2lt4 24012 and sinpi 24013. Existence part. (Contributed by Paul Chapman, 23-Jan-2008.) (Proof shortened by Mario Carneiro, 18-Jun-2014.) (Revised by AV, 14-Sep-2020.) |
⊢ (π ∈ (2(,)4) ∧ (sin‘π) = 0) | ||
Theorem | pigt2lt4 24012 | π is between 2 and 4. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 9-May-2014.) |
⊢ (2 < π ∧ π < 4) | ||
Theorem | sinpi 24013 | The sine of π is 0. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (sin‘π) = 0 | ||
Theorem | pire 24014 | π is a real number. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ π ∈ ℝ | ||
Theorem | picn 24015 | π is a complex number. (Contributed by David A. Wheeler, 6-Dec-2018.) |
⊢ π ∈ ℂ | ||
Theorem | pipos 24016 | π is positive. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 9-May-2014.) |
⊢ 0 < π | ||
Theorem | pirp 24017 | π is a positive real. (Contributed by Glauco Siliprandi, 11-Dec-2019.) |
⊢ π ∈ ℝ+ | ||
Theorem | negpicn 24018 | -π is a real number (common case). (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ -π ∈ ℂ | ||
Theorem | sinhalfpilem 24019 | Lemma for sinhalfpi 24024 and coshalfpi 24025. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ ((sin‘(π / 2)) = 1 ∧ (cos‘(π / 2)) = 0) | ||
Theorem | halfpire 24020 | π / 2 is real. (Contributed by David Moews, 28-Feb-2017.) |
⊢ (π / 2) ∈ ℝ | ||
Theorem | neghalfpire 24021 | -π / 2 is real. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ -(π / 2) ∈ ℝ | ||
Theorem | neghalfpirx 24022 | -π / 2 is an extended real. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ -(π / 2) ∈ ℝ* | ||
Theorem | pidiv2halves 24023 | Adding π / 2 to itself is π (common case). See 2halves 11137. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ ((π / 2) + (π / 2)) = π | ||
Theorem | sinhalfpi 24024 | The sine of π / 2 is 1. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (sin‘(π / 2)) = 1 | ||
Theorem | coshalfpi 24025 | The cosine of π / 2 is 0. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (cos‘(π / 2)) = 0 | ||
Theorem | cosneghalfpi 24026 | The cosine of -π / 2 is zero. (Contributed by David Moews, 28-Feb-2017.) |
⊢ (cos‘-(π / 2)) = 0 | ||
Theorem | efhalfpi 24027 | The exponential of iπ / 2 is i. (Contributed by Mario Carneiro, 9-May-2014.) |
⊢ (exp‘(i · (π / 2))) = i | ||
Theorem | cospi 24028 | The cosine of π is -1. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (cos‘π) = -1 | ||
Theorem | efipi 24029 | The exponential of i · π. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (exp‘(i · π)) = -1 | ||
Theorem | eulerid 24030 | Euler's identity. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 9-May-2014.) |
⊢ ((exp‘(i · π)) + 1) = 0 | ||
Theorem | sin2pi 24031 | The sine of 2π is 0. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (sin‘(2 · π)) = 0 | ||
Theorem | cos2pi 24032 | The cosine of 2π is 1. (Contributed by Paul Chapman, 23-Jan-2008.) |
⊢ (cos‘(2 · π)) = 1 | ||
Theorem | ef2pi 24033 | The exponential of 2πi is 1. (Contributed by Mario Carneiro, 9-May-2014.) |
⊢ (exp‘(i · (2 · π))) = 1 | ||
Theorem | ef2kpi 24034 | The exponential of 2𝐾πi is 1. (Contributed by Mario Carneiro, 9-May-2014.) |
⊢ (𝐾 ∈ ℤ → (exp‘((i · (2 · π)) · 𝐾)) = 1) | ||
Theorem | efper 24035 | The exponential function is periodic. (Contributed by Paul Chapman, 21-Apr-2008.) (Proof shortened by Mario Carneiro, 10-May-2014.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐾 ∈ ℤ) → (exp‘(𝐴 + ((i · (2 · π)) · 𝐾))) = (exp‘𝐴)) | ||
Theorem | sinperlem 24036 | Lemma for sinper 24037 and cosper 24038. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (𝐴 ∈ ℂ → (𝐹‘𝐴) = (((exp‘(i · 𝐴))𝑂(exp‘(-i · 𝐴))) / 𝐷)) & ⊢ ((𝐴 + (𝐾 · (2 · π))) ∈ ℂ → (𝐹‘(𝐴 + (𝐾 · (2 · π)))) = (((exp‘(i · (𝐴 + (𝐾 · (2 · π)))))𝑂(exp‘(-i · (𝐴 + (𝐾 · (2 · π)))))) / 𝐷)) ⇒ ⊢ ((𝐴 ∈ ℂ ∧ 𝐾 ∈ ℤ) → (𝐹‘(𝐴 + (𝐾 · (2 · π)))) = (𝐹‘𝐴)) | ||
Theorem | sinper 24037 | The sine function is periodic. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐾 ∈ ℤ) → (sin‘(𝐴 + (𝐾 · (2 · π)))) = (sin‘𝐴)) | ||
Theorem | cosper 24038 | The cosine function is periodic. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐾 ∈ ℤ) → (cos‘(𝐴 + (𝐾 · (2 · π)))) = (cos‘𝐴)) | ||
Theorem | sin2kpi 24039 | If 𝐾 is an integer, the sine of 2𝐾π is 0. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (𝐾 ∈ ℤ → (sin‘(𝐾 · (2 · π))) = 0) | ||
Theorem | cos2kpi 24040 | If 𝐾 is an integer, the cosine of 2𝐾π is 1. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (𝐾 ∈ ℤ → (cos‘(𝐾 · (2 · π))) = 1) | ||
Theorem | sin2pim 24041 | Sine of a number subtracted from 2 · π. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ ℂ → (sin‘((2 · π) − 𝐴)) = -(sin‘𝐴)) | ||
Theorem | cos2pim 24042 | Cosine of a number subtracted from 2 · π. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ ℂ → (cos‘((2 · π) − 𝐴)) = (cos‘𝐴)) | ||
Theorem | sinmpi 24043 | Sine of a number less π. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ ℂ → (sin‘(𝐴 − π)) = -(sin‘𝐴)) | ||
Theorem | cosmpi 24044 | Cosine of a number less π. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ ℂ → (cos‘(𝐴 − π)) = -(cos‘𝐴)) | ||
Theorem | sinppi 24045 | Sine of a number plus π. (Contributed by NM, 10-Aug-2008.) |
⊢ (𝐴 ∈ ℂ → (sin‘(𝐴 + π)) = -(sin‘𝐴)) | ||
Theorem | cosppi 24046 | Cosine of a complex number plus π. (Contributed by NM, 18-Aug-2008.) |
⊢ (𝐴 ∈ ℂ → (cos‘(𝐴 + π)) = -(cos‘𝐴)) | ||
Theorem | efimpi 24047 | The exponential function of i times a real number less π. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ ℂ → (exp‘(i · (𝐴 − π))) = -(exp‘(i · 𝐴))) | ||
Theorem | sinhalfpip 24048 | The sine of π / 2 plus a number. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ℂ → (sin‘((π / 2) + 𝐴)) = (cos‘𝐴)) | ||
Theorem | sinhalfpim 24049 | The sine of π / 2 minus a number. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ℂ → (sin‘((π / 2) − 𝐴)) = (cos‘𝐴)) | ||
Theorem | coshalfpip 24050 | The cosine of π / 2 plus a number. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ℂ → (cos‘((π / 2) + 𝐴)) = -(sin‘𝐴)) | ||
Theorem | coshalfpim 24051 | The cosine of π / 2 minus a number. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ℂ → (cos‘((π / 2) − 𝐴)) = (sin‘𝐴)) | ||
Theorem | ptolemy 24052 | Ptolemy's Theorem. This theorem is named after the Greek astronomer and mathematician Ptolemy (Claudius Ptolemaeus). This particular version is expressed using the sine function. It is proved by expanding all the multiplication of sines to a product of cosines of differences using sinmul 14741, then using algebraic simplification to show that both sides are equal. This formalization is based on the proof in "Trigonometry" by Gelfand and Saul. This is Metamath 100 proof #95. (Contributed by David A. Wheeler, 31-May-2015.) |
⊢ (((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ) ∧ (𝐶 ∈ ℂ ∧ 𝐷 ∈ ℂ) ∧ ((𝐴 + 𝐵) + (𝐶 + 𝐷)) = π) → (((sin‘𝐴) · (sin‘𝐵)) + ((sin‘𝐶) · (sin‘𝐷))) = ((sin‘(𝐵 + 𝐶)) · (sin‘(𝐴 + 𝐶)))) | ||
Theorem | sincosq1lem 24053 | Lemma for sincosq1sgn 24054. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴 ∧ 𝐴 < (π / 2)) → 0 < (sin‘𝐴)) | ||
Theorem | sincosq1sgn 24054 | The signs of the sine and cosine functions in the first quadrant. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ (0(,)(π / 2)) → (0 < (sin‘𝐴) ∧ 0 < (cos‘𝐴))) | ||
Theorem | sincosq2sgn 24055 | The signs of the sine and cosine functions in the second quadrant. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ((π / 2)(,)π) → (0 < (sin‘𝐴) ∧ (cos‘𝐴) < 0)) | ||
Theorem | sincosq3sgn 24056 | The signs of the sine and cosine functions in the third quadrant. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ (π(,)(3 · (π / 2))) → ((sin‘𝐴) < 0 ∧ (cos‘𝐴) < 0)) | ||
Theorem | sincosq4sgn 24057 | The signs of the sine and cosine functions in the fourth quadrant. (Contributed by Paul Chapman, 24-Jan-2008.) |
⊢ (𝐴 ∈ ((3 · (π / 2))(,)(2 · π)) → ((sin‘𝐴) < 0 ∧ 0 < (cos‘𝐴))) | ||
Theorem | coseq00topi 24058 | Location of the zeroes of cosine in (0[,]π). (Contributed by David Moews, 28-Feb-2017.) |
⊢ (𝐴 ∈ (0[,]π) → ((cos‘𝐴) = 0 ↔ 𝐴 = (π / 2))) | ||
Theorem | coseq0negpitopi 24059 | Location of the zeroes of cosine in (-π(,]π). (Contributed by David Moews, 28-Feb-2017.) |
⊢ (𝐴 ∈ (-π(,]π) → ((cos‘𝐴) = 0 ↔ 𝐴 ∈ {(π / 2), -(π / 2)})) | ||
Theorem | tanrpcl 24060 | Positive real closure of the tangent function. (Contributed by Mario Carneiro, 29-Jul-2014.) |
⊢ (𝐴 ∈ (0(,)(π / 2)) → (tan‘𝐴) ∈ ℝ+) | ||
Theorem | tangtx 24061 | The tangent function is greater than its argument on positive reals in its principal domain. (Contributed by Mario Carneiro, 29-Jul-2014.) |
⊢ (𝐴 ∈ (0(,)(π / 2)) → 𝐴 < (tan‘𝐴)) | ||
Theorem | tanabsge 24062 | The tangent function is greater than or equal to its argument in absolute value. (Contributed by Mario Carneiro, 25-Feb-2015.) |
⊢ (𝐴 ∈ (-(π / 2)(,)(π / 2)) → (abs‘𝐴) ≤ (abs‘(tan‘𝐴))) | ||
Theorem | sinq12gt0 24063 | The sine of a number strictly between 0 and π is positive. (Contributed by Paul Chapman, 15-Mar-2008.) |
⊢ (𝐴 ∈ (0(,)π) → 0 < (sin‘𝐴)) | ||
Theorem | sinq12ge0 24064 | The sine of a number between 0 and π is nonnegative. (Contributed by Mario Carneiro, 13-May-2014.) |
⊢ (𝐴 ∈ (0[,]π) → 0 ≤ (sin‘𝐴)) | ||
Theorem | sinq34lt0t 24065 | The sine of a number strictly between π and 2 · π is negative. (Contributed by NM, 17-Aug-2008.) |
⊢ (𝐴 ∈ (π(,)(2 · π)) → (sin‘𝐴) < 0) | ||
Theorem | cosq14gt0 24066 | The cosine of a number strictly between -π / 2 and π / 2 is positive. (Contributed by Mario Carneiro, 25-Feb-2015.) |
⊢ (𝐴 ∈ (-(π / 2)(,)(π / 2)) → 0 < (cos‘𝐴)) | ||
Theorem | cosq14ge0 24067 | The cosine of a number between -π / 2 and π / 2 is nonnegative. (Contributed by Mario Carneiro, 13-May-2014.) |
⊢ (𝐴 ∈ (-(π / 2)[,](π / 2)) → 0 ≤ (cos‘𝐴)) | ||
Theorem | sincosq1eq 24068 | Complementarity of the sine and cosine functions in the first quadrant. (Contributed by Paul Chapman, 25-Jan-2008.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ (𝐴 + 𝐵) = 1) → (sin‘(𝐴 · (π / 2))) = (cos‘(𝐵 · (π / 2)))) | ||
Theorem | sincos4thpi 24069 | The sine and cosine of π / 4. (Contributed by Paul Chapman, 25-Jan-2008.) |
⊢ ((sin‘(π / 4)) = (1 / (√‘2)) ∧ (cos‘(π / 4)) = (1 / (√‘2))) | ||
Theorem | tan4thpi 24070 | The tangent of π / 4. (Contributed by Mario Carneiro, 5-Apr-2015.) |
⊢ (tan‘(π / 4)) = 1 | ||
Theorem | sincos6thpi 24071 | The sine and cosine of π / 6. (Contributed by Paul Chapman, 25-Jan-2008.) Replace OLD theorem. (Revised by Wolf Lammen, 24-Sep-2020.) |
⊢ ((sin‘(π / 6)) = (1 / 2) ∧ (cos‘(π / 6)) = ((√‘3) / 2)) | ||
Theorem | sincos3rdpi 24072 | The sine and cosine of π / 3. (Contributed by Mario Carneiro, 21-May-2016.) |
⊢ ((sin‘(π / 3)) = ((√‘3) / 2) ∧ (cos‘(π / 3)) = (1 / 2)) | ||
Theorem | pige3 24073 | π is greater or equal to 3. This proof is based on the geometric observation that a hexagon of unit side length has perimeter 6, which is less than the unit-radius circumcircle, of perimeter 2π. We translate this to algebra by looking at the function e↑(i𝑥) as 𝑥 goes from 0 to π / 3; it moves at unit speed and travels distance 1, hence 1 ≤ π / 3. (Contributed by Mario Carneiro, 21-May-2016.) |
⊢ 3 ≤ π | ||
Theorem | abssinper 24074 | The absolute value of sine has period π. (Contributed by NM, 17-Aug-2008.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐾 ∈ ℤ) → (abs‘(sin‘(𝐴 + (𝐾 · π)))) = (abs‘(sin‘𝐴))) | ||
Theorem | sinkpi 24075 | The sine of an integer multiple of π is 0. (Contributed by NM, 11-Aug-2008.) |
⊢ (𝐾 ∈ ℤ → (sin‘(𝐾 · π)) = 0) | ||
Theorem | coskpi 24076 | The absolute value of the cosine of an integer multiple of π is 1. (Contributed by NM, 19-Aug-2008.) |
⊢ (𝐾 ∈ ℤ → (abs‘(cos‘(𝐾 · π))) = 1) | ||
Theorem | sineq0 24077 | A complex number whose sine is zero is an integer multiple of π. (Contributed by NM, 17-Aug-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (𝐴 ∈ ℂ → ((sin‘𝐴) = 0 ↔ (𝐴 / π) ∈ ℤ)) | ||
Theorem | coseq1 24078 | A complex number whose cosine is one is an integer multiple of 2π. (Contributed by Mario Carneiro, 12-May-2014.) |
⊢ (𝐴 ∈ ℂ → ((cos‘𝐴) = 1 ↔ (𝐴 / (2 · π)) ∈ ℤ)) | ||
Theorem | efeq1 24079 | A complex number whose exponential is one is an integer multiple of 2πi. (Contributed by NM, 17-Aug-2008.) (Revised by Mario Carneiro, 10-May-2014.) |
⊢ (𝐴 ∈ ℂ → ((exp‘𝐴) = 1 ↔ (𝐴 / (i · (2 · π))) ∈ ℤ)) | ||
Theorem | cosne0 24080 | The cosine function has no zeroes within the vertical strip of the complex plane between real part -π / 2 and π / 2. (Contributed by Mario Carneiro, 2-Apr-2015.) |
⊢ ((𝐴 ∈ ℂ ∧ (ℜ‘𝐴) ∈ (-(π / 2)(,)(π / 2))) → (cos‘𝐴) ≠ 0) | ||
Theorem | cosordlem 24081 | Lemma for cosord 24082. (Contributed by Mario Carneiro, 10-May-2014.) |
⊢ (𝜑 → 𝐴 ∈ (0[,]π)) & ⊢ (𝜑 → 𝐵 ∈ (0[,]π)) & ⊢ (𝜑 → 𝐴 < 𝐵) ⇒ ⊢ (𝜑 → (cos‘𝐵) < (cos‘𝐴)) | ||
Theorem | cosord 24082 | Cosine is decreasing over the closed interval from 0 to π. (Contributed by Paul Chapman, 16-Mar-2008.) (Proof shortened by Mario Carneiro, 10-May-2014.) |
⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 < 𝐵 ↔ (cos‘𝐵) < (cos‘𝐴))) | ||
Theorem | cos11 24083 | Cosine is one-to-one over the closed interval from 0 to π. (Contributed by Paul Chapman, 16-Mar-2008.) (Proof shortened by Mario Carneiro, 10-May-2014.) |
⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 = 𝐵 ↔ (cos‘𝐴) = (cos‘𝐵))) | ||
Theorem | sinord 24084 | Sine is increasing over the closed interval from -(π / 2) to (π / 2). (Contributed by Mario Carneiro, 29-Jul-2014.) |
⊢ ((𝐴 ∈ (-(π / 2)[,](π / 2)) ∧ 𝐵 ∈ (-(π / 2)[,](π / 2))) → (𝐴 < 𝐵 ↔ (sin‘𝐴) < (sin‘𝐵))) | ||
Theorem | recosf1o 24085 | The cosine function is a bijection when restricted to its principal domain. (Contributed by Mario Carneiro, 12-May-2014.) |
⊢ (cos ↾ (0[,]π)):(0[,]π)–1-1-onto→(-1[,]1) | ||
Theorem | resinf1o 24086 | The sine function is a bijection when restricted to its principal domain. (Contributed by Mario Carneiro, 12-May-2014.) |
⊢ (sin ↾ (-(π / 2)[,](π / 2))):(-(π / 2)[,](π / 2))–1-1-onto→(-1[,]1) | ||
Theorem | tanord1 24087 | The tangent function is strictly increasing on the nonnegative part of its principal domain. (Lemma for tanord 24088.) (Contributed by Mario Carneiro, 29-Jul-2014.) Revised to replace an OLD theorem. (Revised by Wolf Lammen, 20-Sep-2020.) |
⊢ ((𝐴 ∈ (0[,)(π / 2)) ∧ 𝐵 ∈ (0[,)(π / 2))) → (𝐴 < 𝐵 ↔ (tan‘𝐴) < (tan‘𝐵))) | ||
Theorem | tanord 24088 | The tangent function is strictly increasing on its principal domain. (Contributed by Mario Carneiro, 4-Apr-2015.) |
⊢ ((𝐴 ∈ (-(π / 2)(,)(π / 2)) ∧ 𝐵 ∈ (-(π / 2)(,)(π / 2))) → (𝐴 < 𝐵 ↔ (tan‘𝐴) < (tan‘𝐵))) | ||
Theorem | tanregt0 24089 | The positivity of tan(𝐴) extends to complex numbers with the same real part. (Contributed by Mario Carneiro, 5-Apr-2015.) |
⊢ ((𝐴 ∈ ℂ ∧ (ℜ‘𝐴) ∈ (0(,)(π / 2))) → 0 < (ℜ‘(tan‘𝐴))) | ||
Theorem | negpitopissre 24090 | (-π(,]π) is a subset of the reals. (Contributed by David Moews, 28-Feb-2017.) |
⊢ (-π(,]π) ⊆ ℝ | ||
Theorem | efgh 24091* | The exponential function of a scaled complex number is a group homomorphism from the group of complex numbers under addition to the set of complex numbers under multiplication. (Contributed by Paul Chapman, 25-Apr-2008.) (Revised by Mario Carneiro, 11-May-2014.) (Revised by Thierry Arnoux, 26-Jan-2020.) |
⊢ 𝐹 = (𝑥 ∈ 𝑋 ↦ (exp‘(𝐴 · 𝑥))) ⇒ ⊢ (((𝐴 ∈ ℂ ∧ 𝑋 ∈ (SubGrp‘ℂfld)) ∧ 𝐵 ∈ 𝑋 ∧ 𝐶 ∈ 𝑋) → (𝐹‘(𝐵 + 𝐶)) = ((𝐹‘𝐵) · (𝐹‘𝐶))) | ||
Theorem | efif1olem1 24092* | Lemma for efif1o 24096. (Contributed by Mario Carneiro, 13-May-2014.) |
⊢ 𝐷 = (𝐴(,](𝐴 + (2 · π))) ⇒ ⊢ ((𝐴 ∈ ℝ ∧ (𝑥 ∈ 𝐷 ∧ 𝑦 ∈ 𝐷)) → (abs‘(𝑥 − 𝑦)) < (2 · π)) | ||
Theorem | efif1olem2 24093* | Lemma for efif1o 24096. (Contributed by Mario Carneiro, 13-May-2014.) |
⊢ 𝐷 = (𝐴(,](𝐴 + (2 · π))) ⇒ ⊢ ((𝐴 ∈ ℝ ∧ 𝑧 ∈ ℝ) → ∃𝑦 ∈ 𝐷 ((𝑧 − 𝑦) / (2 · π)) ∈ ℤ) | ||
Theorem | efif1olem3 24094* | Lemma for efif1o 24096. (Contributed by Mario Carneiro, 8-May-2015.) |
⊢ 𝐹 = (𝑤 ∈ 𝐷 ↦ (exp‘(i · 𝑤))) & ⊢ 𝐶 = (◡abs “ {1}) ⇒ ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐶) → (ℑ‘(√‘𝑥)) ∈ (-1[,]1)) | ||
Theorem | efif1olem4 24095* | The exponential function of an imaginary number maps any interval of length 2π one-to-one onto the unit circle. (Contributed by Paul Chapman, 16-Mar-2008.) (Proof shortened by Mario Carneiro, 13-May-2014.) |
⊢ 𝐹 = (𝑤 ∈ 𝐷 ↦ (exp‘(i · 𝑤))) & ⊢ 𝐶 = (◡abs “ {1}) & ⊢ (𝜑 → 𝐷 ⊆ ℝ) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐷 ∧ 𝑦 ∈ 𝐷)) → (abs‘(𝑥 − 𝑦)) < (2 · π)) & ⊢ ((𝜑 ∧ 𝑧 ∈ ℝ) → ∃𝑦 ∈ 𝐷 ((𝑧 − 𝑦) / (2 · π)) ∈ ℤ) & ⊢ 𝑆 = (sin ↾ (-(π / 2)[,](π / 2))) ⇒ ⊢ (𝜑 → 𝐹:𝐷–1-1-onto→𝐶) | ||
Theorem | efif1o 24096* | The exponential function of an imaginary number maps any open-below, closed-above interval of length 2π one-to-one onto the unit circle. (Contributed by Paul Chapman, 16-Mar-2008.) (Revised by Mario Carneiro, 13-May-2014.) |
⊢ 𝐹 = (𝑤 ∈ 𝐷 ↦ (exp‘(i · 𝑤))) & ⊢ 𝐶 = (◡abs “ {1}) & ⊢ 𝐷 = (𝐴(,](𝐴 + (2 · π))) ⇒ ⊢ (𝐴 ∈ ℝ → 𝐹:𝐷–1-1-onto→𝐶) | ||
Theorem | efifo 24097* | The exponential function of an imaginary number maps the reals onto the unit circle. (Contributed by Mario Carneiro, 13-May-2014.) |
⊢ 𝐹 = (𝑧 ∈ ℝ ↦ (exp‘(i · 𝑧))) & ⊢ 𝐶 = (◡abs “ {1}) ⇒ ⊢ 𝐹:ℝ–onto→𝐶 | ||
Theorem | eff1olem 24098* | The exponential function maps the set 𝑆, of complex numbers with imaginary part in a real interval of length 2 · π, one-to-one onto the nonzero complex numbers. (Contributed by Paul Chapman, 16-Apr-2008.) (Proof shortened by Mario Carneiro, 13-May-2014.) |
⊢ 𝐹 = (𝑤 ∈ 𝐷 ↦ (exp‘(i · 𝑤))) & ⊢ 𝑆 = (◡ℑ “ 𝐷) & ⊢ (𝜑 → 𝐷 ⊆ ℝ) & ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐷 ∧ 𝑦 ∈ 𝐷)) → (abs‘(𝑥 − 𝑦)) < (2 · π)) & ⊢ ((𝜑 ∧ 𝑧 ∈ ℝ) → ∃𝑦 ∈ 𝐷 ((𝑧 − 𝑦) / (2 · π)) ∈ ℤ) ⇒ ⊢ (𝜑 → (exp ↾ 𝑆):𝑆–1-1-onto→(ℂ ∖ {0})) | ||
Theorem | eff1o 24099 | The exponential function maps the set 𝑆, of complex numbers with imaginary part in the closed-above, open-below interval from -π to π one-to-one onto the nonzero complex numbers. (Contributed by Paul Chapman, 16-Apr-2008.) (Revised by Mario Carneiro, 13-May-2014.) |
⊢ 𝑆 = (◡ℑ “ (-π(,]π)) ⇒ ⊢ (exp ↾ 𝑆):𝑆–1-1-onto→(ℂ ∖ {0}) | ||
Theorem | efabl 24100* | The image of a subgroup of the group +, under the exponential function of a scaled complex number, is an Abelian group. (Contributed by Paul Chapman, 25-Apr-2008.) (Revised by Mario Carneiro, 12-May-2014.) (Revised by Thierry Arnoux, 26-Jan-2020.) |
⊢ 𝐹 = (𝑥 ∈ 𝑋 ↦ (exp‘(𝐴 · 𝑥))) & ⊢ 𝐺 = ((mulGrp‘ℂfld) ↾s ran 𝐹) & ⊢ (𝜑 → 𝐴 ∈ ℂ) & ⊢ (𝜑 → 𝑋 ∈ (SubGrp‘ℂfld)) ⇒ ⊢ (𝜑 → 𝐺 ∈ Abel) |
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