If 0 < x < 2 π , then which is greater?
A = sin ( cos x )
B = cos ( sin x )
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B = cos ( sin x ) = sin ( 2 π − sin x ) . Since sin x + cos x = 2 sin ( x + 4 π ) ≤ 2 < 2 π . Then 2 π − sin x > cos x . Therefore, B = sin ( 2 π − sin x ) > sin ( cos x ) = A or B > A .
Sir,please check my solution
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I'm not sure. At first I was also trying this approach.
Ok sir,thanks for paying attention
In the folllowing range we can,say that sinx<x......(1) ..so,cos(sinx)>cosx.....(2) Put...x=cosx in equation 1.. So,cosx>sin(cosx)......(3) Therefore, Cos(sinx)>sin(cosx)......... Please comment if you figure out some mistake
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sin x + cos x ≤ 2 < 2 π (since 3 < π < 4 and 8 < 9 ⟹ 2 < 1 . 5 ), therefore cos x < 2 π − sin x ⟹ sin ( cos x ) < sin ( 2 π − sin x ) = cos ( sin x )