If \(x+2y=8\) then the maximum value of \(xy\) is1\(20\)2\(16\)3\(24\)4\(8\)Answer & explanation+Correct answer: option 4Let \(f(y)=(8-2y)y=8y-2y^{2}\) \(f^{\prime}(y)=8-4y,f^{\prime}(y)=0\Rightarrow y=2\hspace{7cm}\) Max \((f(y))=16-8=8\)
