# Trigonometry help ! !

## Homework Statement

will sum1 prove this ........@=theta
1-cos@ / sin@ = tan(@/2)

## The Attempt at a Solution

i tried to do this
cos@ = cos^2(@/2) - sin^2 (@/2)
wat now?
...
thats doesnt get me anywhere

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Since you have a half angle on the right side, you'll want to convert all angles into their half angle equivalents. For example, $$\sin(2x)=2\sin(x)\cos(x)$$ therefore $$\sin(\theta)=2\sin\left(\frac{\theta}{2}\right) \cos \left(\frac{\theta}{2}\right)$$