Test:211 QNo:2

(4cos²9-3)(4sin²63-3)=?

3 Answers

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.cos3Î¸.(-sin63).sin3Î¸
= cos 9Â° cos 27Â° sin 63Â° sin 9Â°

But the answer is not coming.

Pls tell me where I went wrong.

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!

The correct answer is (a) tan 9 !

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