Question

Evaluate sin²5°+sin²10°......+sin²85°+cos²45°

Answer 1

Answer:

sin^5+sin^10+.....+sin^40+sin^45+sin^50+.....sin^80+sin^85+cos^45

since cos^B+sin^B=1, and sinA=cos(90-A)

=sin^5+sin^10+.....+sin^40+cos^40+cos^35+...+cos^10+cos^5+1

=1×(40/5)+1

=9=Ans.

Step-by-step explanation:

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