Q.
If cot2Acot2B=3, then the value of (2 - cos 2A) (2 - cos 2B) is ___________.
see full answer
Start JEE / NEET / Foundation preparation at rupees 99/day !!
21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya
answer is 3.
(Unlock A.I Detailed Solution for FREE)
Ready to Test Your Skills?
Check your Performance Today with our Free Mock Test used by Toppers!
Take Free Test
Detailed Solution
(2−cos2A)(2−cos2B) =1+2sin2A1+2sin2B =1+2sin2A+sin2B+4sin2Asin2B …….. (1)Now, cot2A cot2B=3⇒ cos2Acos2B=3sin2Asin2B⇒ 1−sin2A1−sin2B=3sin2Asin2B⇒ sin2A+sin2B+2sin2Asin2B=1From (1), we get(2−cos2A)(2−cos2B)=1+2=3
Watch 3-min video & get full concept clarity