Question 264 of 298MediumMCQ
If A=sin2x+cos4x, then for all real x: Solutions · 1
Official solution
\[A = \sin^2x+\cos^2x(1-\sin^2x) = 1-\frac14(2\sin x\cos x)^2 = 1-\frac14\sin^22x\]
Since sin22x∈[0,1]: A∈[1−41, 1]=[43,1] Answer the question to unlock