Better Late Than Never

Well, I finally figured out how to do these examples! I may not get marks for them, but I guess the main thing is that I know how to do them.

Example One: Determine the exact value of sin135
sin(90+45)=sin90 cos45 + cos90 sin45
= (pi/2)(sqrt.2/2) + (0)(sqrt.2/2)
=(sqrt.2)(pi)/4

Example Two: Simplify: sin6xsin4x - cos6xcos4x
= -(cos6xcos4x-sin6xsin4x)
= -cos(6x+ 4x)
= -cos10x


Amy