Question

evaluate : sec41 .sin49+cos49.cosec41-2/√3 tan20.tan60.tan70-3(cos square 45-- sin square 90)
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Answer 1

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Sec 41× sin(90-41) + cos(90-41)× cosec41 - 2 / 3^1/2 × tan (90-70)× 3^1/2 × tan 70 - 3(1/2 -1)

=( sec 41× cos 41 )+( sin 41× cosec 41 )-(2× cot70 × tan70) -3(-1/2)

= 1 + 1 - 2 + 3/2

= 3/2.

Sin(90-x)= cos x

Cos(90-x) = sin x

Tan(90-x)= cot x

Cotx × tanx =1

Sin × cosec=1

Cos × sec=1

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