- #1
Rectifier
Gold Member
- 313
- 4
The problem
Show that the left side is equal to right side
## tan (\frac{x}{2}) = \frac{1-cos(x)}{sin(x)} ##
The attempt
##\tan(\frac{x}{2}) = \frac{ sin(\frac{x}{2}) }{ cos (\frac{x}{2}) } = \frac{ sin^2(\frac{x}{2}) }{ cos ^2 (\frac{x}{2}) } = \frac{\frac{1-cos(x)}{2}}{\frac{1+cos(x)}{2}} = \frac{1-cos(x)}{1+cos(x)} ## Fail :,(