Trigonometry
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JMAP[1]
Circle
\( (\color{blue}{\cos} \: \theta ,\color{red}{\sin}\: \theta) \)
Radians
To Convert Degrees in Radian with \(\pi \) Terms
Convert 12° to radians with \(\pi \) terms.
- Multiply 12° by \( \pi/180 \).
- Drop the °.
- Reduce.
- Simplify.
$$ 12^{\circ} \times \frac{\pi}{180} $$ | $$=\frac{ 12^{\circ}\pi}{180} $$ |
$$=\frac{ 12\pi}{180} $$ | |
$$=\frac{ \pi}{15} $$ |
Derivative
Integrals
$$ \int \sin x \: dx$$ | $$= - \cos x + C$$ | $$\int \arcsin x \: dx $$ | $$= x \arcsin x + \sqrt{1-x^{2}} +C \:\:\:\: $$ | $$\int \frac{1}{\sqrt{a^{2}-x^{2}}} \: dx $$ | $$= \arcsin \frac{x}{a} + C $$ |
$$ \int \cos x \: dx$$ | $$= \sin x $$ | $$\int \arccos x \: dx $$ | $$= x \arccos x - \sqrt{1-x^{2}} +C $$ | ||
$$ \int \tan x \: dx $$ | $$= - \ln (\cos x) + C $$ | $$ \int \arctan x \:dx $$ | $$= x \arctan x - \frac{1}{2} \ln(1+x^{2})+ C \:\:\:\: $$ | $$\int \frac{1}{a^{2}+x^{2}} \: dx $$ | $$= \frac{1}{a} \arctan \frac{x}{a} +C$$ |
$$ \int \cot x \: dx$$ | $$= \ln (\sin x) + C$$ | $$ \int \text{arccot } x \: dx $$ | $$= x \text{ arccot }x + \frac{1}{2} \ln(1+x^{2})+ C $$ | ||
$$ \int \sec x \: dx$$ | $$= \ln ( \sec x + \tan x) + C$$ | $$ \int \text{arcsec } x \: dx $$ | $$= x \text{ arcsec } x - \ln \left[ x \left( 1+ \frac{x^{2}-1}{x^{2}} \right)\right]+C \:\:\:\: $$ | $$\int \frac{1}{x\sqrt{x^{2}-a^{2}}} \:dx $$ | $$= \frac{1}{a} \text{arcsec} \frac{x}{a} +C $$ |
$$ \int \csc x \: dx$$ | $$= - \ln( \csc x + \cot x ) +C \:\:\:\: $$ | $$\int \text{ arccsc } x \: dx $$ | $$= x \text{ arccsc } x + \ln \left[ x \left( 1+ \frac{x^{2}-1}{x^{2}} \right)\right]+C $$ | ||
$$ \int \sec^{2} x \: dx$$ | $$= \tan x +C $$ | ||||
$$ \int \csc^{2} x \: dx$$ | $$= -\cot x + C$$ | ||||
$$\int x \cos x \:dx $$ | $$= x \sin x + \cos x $$ | ||||
$$\int x \sin x \:dx $$ | $$= - x \cos x + \sin x $$ | ||||
$$\int x \tan x \:dx $$ | $$= \frac{1}{2} i \left( Li ( -e^{2ix}) + x^{2}+ 2ix \ln(1+e^{2ix})\right) $$ | ||||
Identities
Inverse Trigonometric Functions[2]
Inverse trigonometric functions are the opposite for the function.
Name | Usual notation | Definition | Domain of x for real result | Range of usual principal value (radians) |
Range of usual principal value (degrees) |
---|---|---|---|---|---|
arcsine | \(y = \arcsin(x), \: \sin^{-1}\) | \(x = \sin(y) \) | \(−1 \leqslant x \leqslant 1 \) | \(−\frac{\pi}{2} \leqslant y \leqslant \frac{\pi}{2}\) | \( −90° \leqslant y \leqslant 90° \) |
arccosine | \( y = \arccos(x), \: \cos^{-1} \) | \( x = \cos(y)\) | \(−1 \leqslant x \leqslant 1 \) | \(0 \leqslant y \leqslant \pi \) | \(0° \leqslant y \leqslant 180° \) |
arctangent | \(y = \arctan(x), \: \tan^{-1}\) | \(x = \tan(y)\) | all real numbers | \(−\frac{\pi}{2} < y < \frac{\pi}{2} \) | \(−90° < y < 90° \) |
arccotangent | \(y = \text{arccot}(x), \: \cot^{-1}\) | \(x = \cot(y)\) | all real numbers | \( 0 < y < \pi\) | \(0° < y < 180° \) |
arcsecant | \(y = \text{arcsec }(x), \: \sec^{-1}\) | \(x = \sec(y) \) | \( x \leqslant −1 \) or \( 1 \leqslant x \) | \( 0 \leqslant y < \frac{\pi}{2} \) or \(\frac{\pi}{2} < y \leqslant \pi \) | \(0° \leqslant y < 90°\) or \( 90° < y \leqslant 180°\) |
arccosecant | \( y = \text{arccsc}(x), \: \csc^{-1} \) | \(x = \csc(y)\) | \( x \leqslant −1 \) or \( 1 \leqslant x \) | \(−\frac{\pi}{2} \leqslant y < 0 \) or \( 0 < y \leqslant \frac{\pi}{2} \) | \(−90° \leqslant y < 0°\) or \( 0° < y \leqslant 90° \) |
Triangle
Trigonometry as a Hexagon
Internal Links
Parent Article: Mathematics