Question

Prove that cos teta sin(90- teta)+sin teta cos(90-teta)=1

Answer 1

Answer:

teta be t for simplicity

costsin(90-t)+cos(90-t)sint

sin(90-t)=cost

cos(90-t)=sint

costcost+sintsint

cos^2t + sin^2t = 1

Answer 2

Answer:

cos^2θ+sin^2θ=1 very simple