Question

Simplify 3cos^2(theta/2)-3. Please show your work!!

Answer 1

Explanation:

`3 \cos { }^(2) ( ( \alpha )/(2) ) - 3`

`3( \cos { \\ }^(2) ( ( \alpha )/(2)) - 1) )`

`- 3( \sin {}^(2) ( ( \alpha )/(2) ) )`

`\sin( ( \alpha )/(2) ) = \sqrt{ (1 - \cos( \alpha ) )/(2) }`

`- 3( (1 - \cos( \alpha ) )/(2) )`

`( - 3 + 3 \cos( \alpha ) )/(2)`

`- 1.5 + 1.5 \cos( \alpha )`

`1.5( \cos( \alpha ) - 1)`