Question

tìm giá trị lớn nhất

C= -/x+2/+4

D=4,5-/x+2/

Answer 1

a, \(C=-\left|x+2\right|+4\le4\)

Dấu " = " khi \(-\left|x+2\right|=0\Rightarrow x=-2\)

Vậy MAX C = 4 khi x = -2

b, \(D=4,5-\left|x+2\right|\le4,5\)

Dấu " = " khi \(-\left|x+2\right|=0\Rightarrow x=-2\)

Vậy MAX D = 4,5 khi x = -2

Answer 2

\(C=-\left|x+2\right|+4\)

\(\left|x+2\right|\ge0\Rightarrow-\left|x+2\right|\le0\)

\(C=-\left|x+2\right|+4\le4\)

Dấu "=" xảy ra khi:

\(-\left|x+2\right|=0\Rightarrow x=-2\)

\(D=4,5-\left|x+2\right|\)

\(\left|x+2\right|\ge0\)

\(D=4,5- \left|x+2\right|\le4,5\)

Dấu "=" xảy ra khi:

\(x+2=0\Rightarrow x=-2\)