Test:211 QNo:2

(4cos29-3)(4sin263-3)=?

3 Answers

1
Bicchuram Aveek ·

Q. Q2 (4cos29-3)(4sin263-3)=?
a) tan 9
b) tan 18
c) sin 45
d) tan 45
Your Answer: (b)
Correct Answer: (a)
Score: -1

I did the following:

cos9(4cos29-3)(-sin63)(3-4sin263)
= cos9.cos3θ.(-sin63).sin3θ
= cos 9° cos 27° sin 63° sin 9°

But the answer is not coming.

Pls tell me where I went wrong.

62
Lokesh Verma ·

I think you have made a small mistake.. you have to divide the expression by cos 9. sin 63.. which i think you have missed out!

1
pjsudharshan ·

The correct answer is (a) tan 9 !

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