Question

TÌM GTLN: (x-3)(1-x)-2 Giúp mik với

Answer 1

\(\left(x-3\right)\left(1-x\right)-2=-x^2+4x-3-2=-x^2+4x-5=-\left(x^2-4x+4\right)-1=-\left(x-2\right)^2-1\le-1\)

\(ĐTXR\Leftrightarrow x=2\)

Answer 2

\(\left(x-3\right)\left(1-x\right)-2=4x-x^2-1=-\left(x^2-4x+4\right)+3=-\left(x-2\right)^2+3\le3\)

Dấu \("="\Leftrightarrow x=2\)