Prove that sin2θ=(x+y)2/4xy possible for real values of x and y only when x is equal to y. x not equal to 0.
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1 Answers
Manish Shankar
·2014-03-11 03:36:56
(x+y)2≥4xy (AM≥GM)
equal being only when x=y
(x+y)2/4xy≥1
=>sin2θ≥1
which is true only when sin2θ=1
- Himanshu Giria yes sir actually i had got it by this method but i was trying by dividing(x+y)2 's each term by 4xy ...
so in that case i was having a bit problm...
Upvote·0· Reply ·2014-03-11 08:07:03