Question

How do you use the angle sum or difference identity to find the exact value of sin15#?

Answer 1

`sin15=sqrt2/4(sqrt3-1)`

Explanation:

rewrite `" "15^0" "` as sum/difference of angles whose values we know. in this case `" "60^0" "&" "45^0`

`sin15=sin(60-45)`

`sin(60-45)=sin60cos45-sin45cos60`

`=sqrt3/2xxsqrt2/2-sqrt2/2xx1/2`

`=sqrt2/4(sqrt3-1)`