Question

[my nguyen]

tim gia tri nho nhat hoac lon nhat cua cac bieu thuc

A=|x+1|+5

B=\(\dfrac{x^2+15}{x^2+3}\)

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(A=\left|x+1\right|+5\ge5\forall x\)

Dấu '=' xảy ra khi x=-1

b: \(B=\dfrac{x^2+3+12}{x^2+3}=1+\dfrac{12}{x^2+3}\le\dfrac{12}{3}+1=4+1=5\)

Dấu '=' xảy ra khi x=0