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Csc ​

Cosecant, the reciprocal of Sin.

✓ checked against that system · ! checked, with disagreements (hover a chip)DLMF4.14.E5Wolfram LanguageCsc!
Csc(x)the cosecant of x, 1sin⁡(x)\frac{1}{\sin(x)}.
SageMathcsc(x)SymPycsc(x)mpmathcsc(x)Juliaenumeratio_ball(_csc, x)
Typed signatures
TypePackageApplies
(complex | quantity) -> numberanalyticreplaces compute-enginealways
(complex | quantity) -> numbercompute-enginealways

Domain: Elementary functions

Details
  • csc⁡(x)=1sin⁡(x)\csc(x) = \frac{1}{\sin(x)}.
  • Odd function, period 2π2\pi, same as Sin.
  • Undefined wherever sin⁡(x)=0\sin(x) = 0, the same poles as Cot.

Examples

6 more kept as data, checked against the oracles
Basic #
live ↗
Incsc⁡(π6)\csc(\frac{π}{6})Out22
live ↗
Incsc⁡(π4)\csc(\frac{π}{4})Out2\sqrt{2}
live ↗
Incsc⁡(π2)\csc(\frac{π}{2})Out11

csc⁡60∘=233\csc 60^\circ = \frac{2\sqrt3}{3}, exactly

live ↗
Incsc⁡(60∘)\csc(60^{∘})Out233\frac{2\sqrt{3}}{3}

A machine-precision argument evaluates numerically

live ↗
Incsc⁡(1.2)\csc(1.2)Out1.072 916 377 709 897 228 711.072\,916\,377\,709\,897\,228\,71
live ↗
InSeries⁡(csc⁡(x),x,0,10)\operatorname{Series}(\csc(x), x, 0, 10)Out1x+x6+7x3360+31x515 120+127x7604 800+73x93 421 440+O(x11)\frac{1}{x}+\frac{x}{6}+\frac{7x^3}{360}+\frac{31x^5}{15\,120}+\frac{127x^7}{604\,800}+\frac{73x^9}{3\,421\,440}+O\left(x^{11}\right)
live ↗
InSeries⁡(csc⁡(x),x,π,5)\operatorname{Series}(\csc(x), x, π, 5)Out−1x−π−x−π6−1360×7(x−π)3−115 120×31(x−π)5+O((x−π)7)-\frac{1}{x-π}-\frac{x-π}{6}-\frac{1}{360}×7(x-π)^3-\frac{1}{15\,120}×31(x-π)^5+O\left((x-π)^7\right)
Scope #

N(...) of an exact argument gives an arbitrary-precision value

live ↗
InN(csc⁡(65))N(\csc(\frac{6}{5}))Out1.072 916 377 709 897 228 711.072\,916\,377\,709\,897\,228\,71

Evaluates at a complex argument

live ↗
Incsc⁡(2.5+i)\csc(2.5+i)Out0.530 965 577 621 174 2+0.541 322 906 190 002 5i0.530\,965\,577\,621\,174\,2+0.541\,322\,906\,190\,002\,5i

Threads element-wise over a matrix, with ComplexInfinity at the pole π\pi

live ↗
Incsc⁡([[π3,π],[π6,−π/2]])\csc(\bigl\lbrack\bigl\lbrack\frac{π}{3}, π\bigr\rbrack, \bigl\lbrack\frac{π}{6}, -π/2\bigr\rbrack\bigr\rbrack)Out[[233,∞~],[2,−1]]\bigl\lbrack\bigl\lbrack\frac{2\sqrt{3}}{3}, \tilde∞\bigr\rbrack, \bigl\lbrack2, -1\bigr\rbrack\bigr\rbrack

csc⁡(π/12)=6+2\csc(\pi/12) = \sqrt6 + \sqrt2

live ↗
Incsc⁡(π12)\csc(\frac{π}{12})Out2+6\sqrt{2}+\sqrt{6}

csc⁡(π/10)=1+5\csc(\pi/10) = 1 + \sqrt5

live ↗
Incsc⁡(π10)\csc(\frac{π}{10})Out1+51+\sqrt{5}
live ↗
Incsc⁡(π5)\csc(\frac{π}{5})Out15105+5\frac{1}{5}\sqrt{10}\sqrt{5+\sqrt{5}}

Interval arithmetic: the image of [π/6,π/3][\pi/6, \pi/3] is [23,2][\tfrac{2}{\sqrt3}, 2]

live ↗
Incsc⁡(Interval(π6,π3))\csc(\mathrm{Interval}(\frac{π}{6}, \frac{π}{3}))OutInterval(233,2)\mathrm{Interval}(\frac{2\sqrt{3}}{3}, 2)

Uncertainty propagation: csc⁡(2±0.01)≈1.0998±0.0050\csc(2 \pm 0.01) \approx 1.0998 \pm 0.0050

live ↗
Incsc⁡(Around(2,0.01))\csc(\mathrm{Around}(2, 0.01))OutAround(1.099 750 170 294 616 4,0.005 033 089 733 443 42)\mathrm{Around}(1.099\,750\,170\,294\,616\,4, 0.005\,033\,089\,733\,443\,42)

Oddness pulls the sign out of a symbolic argument: csc⁡(−x)=−csc⁡x\csc(-x) = -\csc x

live ↗
Incsc⁡(−x)\csc(-x)Out−csc⁡(x)-\csc(x)

Derivative: −csc⁡xcot⁡x-\csc x \cot x

live ↗
Indcsc⁡(x)dx\frac{\mathrm{d}\csc(x)}{\mathrm{d}x}Out−(csc⁡(x)cot⁡(x))-(\csc(x)\cot(x))

Antiderivative: −ln⁡∣csc⁡x+cot⁡x∣-\ln|\csc x + \cot x|

live ↗
In∫ ⁣csc⁡(x) dx\int\!\csc(x)\, \mathrm{d}xOut−ln⁡(∣csc⁡(x)+cot⁡(x)∣)-\ln(\vert\csc(x)+\cot(x)\vert)

Fifty digits of a rational argument

live ↗
InN(csc⁡(65),50)N(\csc(\frac{6}{5}), 50)Out1.072 916 377 709 897 228 705 116 922 435 239 154 837 639 006 697 81.072\,916\,377\,709\,897\,228\,705\,116\,922\,435\,239\,154\,837\,639\,006\,697\,8

Matrix function with exact rational and radical entries

live ↗
InMatrixFunction(_1⁡↦csc⁡(_1⁡),[[π3,π],[π6,−π2]])\mathrm{MatrixFunction}(\operatorname{\_1}↦\csc(\operatorname{\_1}), \bigl\lbrack\bigl\lbrack\frac{π}{3}, π\bigr\rbrack, \bigl\lbrack\frac{π}{6}, -\frac{π}{2}\bigr\rbrack\bigr\rbrack)Out[[67−2321,67+437],[17+2321,17−437]]\bigl\lbrack\bigl\lbrack\frac{6}{7}-\frac{2\sqrt{3}}{21}, \frac{6}{7}+\frac{4\sqrt{3}}{7}\bigr\rbrack, \bigl\lbrack\frac{1}{7}+\frac{2\sqrt{3}}{21}, \frac{1}{7}-\frac{4\sqrt{3}}{7}\bigr\rbrack\bigr\rbrack

csc⁡(∞)\csc(\infty) is a type error at boxing; Wolfram gives the oscillation range, (−∞,−1]∪[1,∞)(-\infty, -1] \cup [1, \infty)

live ↗
live ↗
InAssuming(m∈Z,Refine(csc⁡(πm)))\mathrm{Assuming}(m∈ℤ, \mathrm{Refine}(\csc(πm)))Outcsc⁡(πm)\csc(πm)
live ↗
InAssuming(m∈Z,FullSimplify(Refine(csc⁡(π(1/2+m)))))\mathrm{Assuming}(m∈ℤ, \mathrm{FullSimplify}(\mathrm{Refine}(\csc(π(1/2+m)))))Outcsc⁡(π(m+12))\csc(π(m+\frac{1}{2}))
live ↗
InFunctionMeromorphic(csc⁡(x),x)\mathrm{FunctionMeromorphic}(\csc(x), x)OutTrue\mathrm{True}
Properties #

Reciprocal of Sin: csc⁡(x)=1sin⁡(x)\csc(x) = \frac{1}{\sin(x)}

live ↗
Incsc⁡(π6)=1sin⁡(π6)\csc(\frac{π}{6})=\frac{1}{\sin(\frac{π}{6})}OutTrue\mathrm{True}

csc⁡(π/8)\csc(\pi/8) as a nested radical

live ↗
Incsc⁡(π8)\csc(\frac{π}{8})Out4+22\sqrt{4+2\sqrt{2}}

Known value · Wolfram MathematicalFunctionData, Csc

csc⁡(3π/10)=5−1\csc(3\pi/10) = \sqrt5 - 1

live ↗
Incsc⁡(3π10)\csc(\frac{3π}{10})Out5−1\sqrt{5}-1

Known value · Wolfram MathematicalFunctionData, Csc

live ↗
Incsc⁡(12)8−2(2csc⁡(1/2)2−2)csc⁡(1)2csc⁡(12)4\csc(\frac{1}{2})^8-2(2\csc(1/2)^2-2)\csc(1)^2\csc(\frac{1}{2})^4Outcsc⁡(12)8−4(csc⁡(1/2)2−1)csc⁡(1)2csc⁡(12)4\csc(\frac{1}{2})^8-4(\csc(1/2)^2-1)\csc(1)^2\csc(\frac{1}{2})^4

Known value · Wolfram MathematicalFunctionData, Csc, FunctionalEquations

live ↗
InN(4(csc⁡(1/2)2−1)csc⁡(1)2)N(4(\csc(1/2)^2-1)\csc(1)^2)Out18.928 462 573 893 558 010 575 088 586 931 068 594 797 618.928\,462\,573\,893\,558\,010\,575\,088\,586\,931\,068\,594\,797\,6

Known value · Wolfram MathematicalFunctionData, Csc, FunctionalEquations

live ↗
InN(csc⁡(1/2+π/2)2)N(\csc(1/2+π/2)^2)Out1.298 446 410 409 524 836 881.298\,446\,410\,409\,524\,836\,88

Known value · Wolfram MathematicalFunctionData, Csc, FunctionalEquations

live ↗
InN(4(csc⁡(2)2−1)csc⁡(4)2)N(4(\csc(2)^2-1)\csc(4)^2)Out1.462 770 359 711 973 446 186 309 480 011 456 569 9481.462\,770\,359\,711\,973\,446\,186\,309\,480\,011\,456\,569\,948

Known value · Wolfram MathematicalFunctionData, Csc, FunctionalEquations

Possible issues #

A pole: sin⁡(0)=0\sin(0) = 0

live ↗
Incsc⁡(0)\csc(0)Out∞~\tilde∞

Csc(ComplexInfinity) is Indeterminate, for the same recurring poles as Tan

live ↗

Known value · DLMF 4.14.10

About
Examples39
Checked againstWolfram Language 30 agree8 differ1 unevaluatedSageMath 29 agree1 unevaluated2 errorSymPy 31 agree3 differmpmath 22 agree3 differ1 errorJulia 23 agree3 errorRust 16 agree7 differ1 error
CrosswalkDLMFWolfram LanguageSageMathSymPympmathJulia

Implementation

mappedsympypackages/oracle/src/mappings.ts
mappedmpmathpackages/oracle/src/mappings.ts
mappedsagepackages/oracle/src/mappings.ts
mappedjuliapackages/oracle/src/mappings.ts
mappedrustpackages/oracle/src/mappings.ts

The reciprocal of sin.

See also: Sin, Sec, Cot