Question

Giúp bài này zới mn ơi !!

Answer 1

Áp dụng BĐT \(\left|a\right|+\left|b\right|\ge\left|a+b\right|\) ta có:

\(K=\left|x-2,13\right|+\left|x+2,56\right|=\left|x-2,13\right|+\left|-\left(x+2,56\right)\right|\)

\(=\left|x-2,13\right|+\left|-x-2,56\right|\ge\left|x-2,13+\left(-x\right)-2,56\right|=4,69\)

Dấu "=" xảy ra khi \(-2,56\le x\le2,13\)

Vậy \(Min_K=4,69\) khi \(-2,56\le x\le2,13\)