Question

Evaluate:
cos60⁰ cos30⁰− sin60⁰ sin30⁰

Answer 1

On substituting the values of various T-ratios, we get:
cos60⁰ cos30⁰− sin60⁰ sin30⁰

^{=`(1/2 xx sqrt(3)/2-sqrt(3)/2 xx1/2)=(sqrt(3)/4 - sqrt(3)/4)=0`}