Question

Cot2B- cos2B=cot2B. cos2B
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Answer 1

Step-by-step explanation:

LS = [(1 - 2sin^2A + 1 - 2sin^2B)/(1 - 2sin^2B - 1 + 2sin^2A)

= (1 - sin^2A - sin^2B)/(sin^2A - sin^2B)

= (cos^2A - sin^2B)/[sin(A + B)sin(A - B)]

= [cos(A + B) cos(A -B)]/[sin(A + B)sin(A - B)]

= cos(A + B) /sin(A + B) * cos(A - B) /sin(A - B)

= cot(A + B) cot(A - B) = RS