Trig Identities: Pythagorean, Sum/Diff, Double, Half-Angle

$\frac{1}{\cos\ x}$

$\frac{1}{\csc\ x}$

$\frac{1}{\sec\ x}$

$\csc\ x$

 $\tan^2x$  

 $\cos\ 2x$  

 $\sin^2x$  

 $\sin\ 2x$  

cos x

sin x

sin 2x

sinx cosx

sin x

cos x

-sin x

-cos x

 $\tan^2x\left(1-\csc^22x\right)$  

 $\frac{\sin^2x}{\cos^2x}-\ \frac{\sin^2x}{\cos^2x}\cdot\frac{1}{\sin^2x}$  

 $\left(\tan x-\csc x\right)\cdot\left(\tan x+\csc x\right)$  

 $\tan^2x\left(\cot^2x\right)$  

 $\left(2-2\sin^2x\right)\left(\frac{1}{\cot^2x}\right)$  

 $\left(2\cos^2x\right)\left(\frac{\sin^2x}{\cos^2x}\right)$  

 $\sin^22x\left(\cot^2x\right)$  

 $\frac{2\cos^2x}{\sec^2x-1}$  

 $\sin^2x$  

 $2\cos^2x-\left(\sin^2x+\cos^2x\right)$  

 $\cos^2x-\sin^2x$  

 $\sin^22x$  

 $\frac{12}{25}$  

 $-\frac{7}{25}$  

 $\frac{7}{25}$  

 $\frac{3\sqrt{10}}{10}$  

cos (90)

sin (90)

cos(50)

sin (50)

sin (10)

cos (10)

sin (90)

cos (90)