`sin(60) cos(15) + cos(60)sin(15)` Write the expression as a sine, cosine, or tangent of an angle.

You need to recognize the formula `sin(a+b) = sin a*cos b + sin b*cos a` . You need to put `a = 60^o` and `b = 15^o` , such that:

`sin(60^o + 15^o) = sin 60^o *cos 15^o + sin 15^o*cos 60^o `

`sin 75^o = sin 60^o *cos 15^o + sin 15^o*cos 60^o `

Hence, the given expression could be evaluated as the sine of the sum of angles `60^o ` and `15^o` ,...

You need to recognize the formula `sin(a+b) = sin a*cos b + sin b*cos a` . You need to put `a = 60^o` and `b = 15^o` , such that:

`sin(60^o + 15^o) = sin 60^o *cos 15^o + sin 15^o*cos 60^o `

`sin 75^o = sin 60^o *cos 15^o + sin 15^o*cos 60^o `

Hence, the given expression could be evaluated as the sine of the sum of angles `60^o ` and `15^o` , such that `sin 60^o *cos 15^o + sin 15^o*cos 60^o = sin 75^o .`