Question

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A=\(sin^222+cos^222\)

B= \(sin^240+sin^250\)

C=\(cos^220+cos^270\)

D= \(tan15.cos75\)

E= tan15.tan72

Answer 1

A=sin²22+cos²22

A=cos² 68+cos²22

A=1.

B=sin²40+sin²50

B=1

C=cos²15+cos²70

C=cos²85

Answer 2

\(D=\dfrac{sin15^0}{cos15^0}\cdot sin15^0=\dfrac{sin^215^0}{cos15^0}\)

\(A=\left(sin^2a+cos^2a\right)=1\)

\(B=sin^240^0+cos^240^0=1\)