Trigonometric Identities ( Trig Identities )

  1. 1
    Prove:
    $$ \tan x\cos x = \sin x$$ ( Using Trig Identities )
  2. 2
    Prove:
    $$ \sin x \left(\frac{\cos x}{\tan x}\right)= \cos^2 x$$
  3. 3
    Prove:
    $$ \cos x= \left(\frac{\sin x}{\tan x}\right)$$
  4. 4
    Prove:
    $$ \frac{1}{\sin^2 x}+ \frac{1}{\cos^2 x}= \frac{1}{\sin^2 x \: \cos^2 x}$$
  5. 5
    Prove:
    $$\tan x + \cot x= \frac{1}{\sin x \: \cos x}$$
  6. 6
    Prove:
    $$ \csc x- \sin x= \cos x \cot x$$
  7. 7
    Prove:
    $$ \frac{1}{\csc^2 x}= \frac{\tan^2 x}{1+\tan^2 x}$$
  8. 8
    Prove:
    $$ \frac{1}{1-\sin x}+\frac{1}{1+\sin x}=2\sec^2 x$$
  9. 9
    Prove:
    $$ \frac{\sin^2 x}{1-\cos x}=1+\cos x$$
  10. 10
    Prove:
    $$ \cos^2 x-\sin^2 x=2\cos^2 x-1$$
  11. 11
    Prove:
    $$ \cos^2 x+\sin^2 x+\tan^2 x=\sec^2 x$$
  12. 12
    Prove:
    $$ \tan^2 x-\sin^2 x=\sin^2 x \: \tan^2 x$$
  13. 13
    Prove:
    $$ (\cos x+\sin x)^2=1+2\sin x \: \cos x$$
  14. 14
    Prove:
    $$ \frac{1+2\sin x \: \cos x}{\sin x+\cos x}=\sin x+\cos x$$
  15. 15
    Prove:
    $$ (1+\tan^2 x)(1-\cos^2 x)=\tan^2 x$$
  16. 16
    Prove:
    $$ \frac{\cos x}{1-\sin x}=\frac{1+\sin x}{\cos x}$$

    Tough question !
  17. 17
    Prove:
    $$ \csc x+\cot x=\frac{\sin x}{1-\cos x}$$

    Another tough question - similar to previous video
  18. 18
    Prove:
    $$ \tan x=\frac{1+\sin x-\cos^2 x}{\cos x+\cos x\sin x}$$

    ( trigonometry / trig )

$$e=mc^2$$