Question

Find value of tan 20.tan 25.tan65.tan70

Answer 1

Tan20*tan70*tan25*tan65

Tan20*tan(90-20)*tan25*tan(90-25)

Tan20*cot20*tan25*cot25

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As we know that cot =1/tan
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(Tan20*1/tan20) *(tan25*1/tan25)


1*1

1


I hope this will help you


-by ABHAY

Answer 2

hi here is ur answer :))

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tan20° tan25°tan65°tan70°
= tan20° × tan65° tan25° tan70°
=tan20° × cot(90°-65°) × tan25° × cot(90°-70°)
=tan20° × 1/tan20° × tan25° × 1/tan25°
=1

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hope helped you :))

SWEATA SAHA :))