Question

Please answer with explanation

Answer 1

`- 1 \: \leqslant \: \cos( \alpha ) \: \leqslant \: 1`


`y \: = \: \cos( (x)/(2) )`

`\cos( \alpha ) \: = \: - 1 \: = \: \cos( (x)/(2) )`

`\alpha \: = \: {\pi }^( c)`

`(x)/(2) \: = \: \pi`

`x \: = \: 2\pi`