Question

content quality answer is needed

Answer 1

a2cos2 + b2sin2 + 2absincos = m2
a2sin2 + b2cos2 - 2absincos =n2


a2(sin2+cos2) +b2(sin2 +cos2) = m2+n2

a2+b2 = m2+n2

Answer 2

option ( d ) is correct

I hope this helps you.

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