Question:

Find exact Value: Sin(15^{o}).

So I know I can use Sin(45^{o}- 30^{o}) which would be (SinA)(SinB) - (CosA)(CosB): ((sqrt(2)/2)(1/2)) - ((sqrt(2)/2)(sqrt(3)/2)). I get the result: (sqrt(2)-sqrt(6))/4 . But the answer in the answer key is similar, but not this answer. At first it seems undistributed, but after making the attempt to do so, there is a negative in the wrong place. Answer Key: (sqrt(2)(sqrt(3)-1)/4.

Can someone point out my error? Or if I'm taking the wrong approach to this.