Question

Answer 1

`A=-4+(x-3)^2`

Vì `(x-3)^2>=0=>A>=-4`

Dấu "=" xảy ra khi `x=3`

vậy `min_A=-4<=>x=3`

`B=1/2-(5x+1)^2`

Vì `(5x+1)^2>=0`

`=>1/2-(5x+1)^2<=1/2`

Dấu "=" xảy ra khi `5x+1=0<=>x=-1/5`

vậy `max_B=1/2<=>x=-1/5`

Answer 2

a, \(A=-4+\left(x-3\right)^2\ge-4\)

Dấu ''='' xảy ra khi x = 3 

b, \(B=-\left(5x+1\right)^2+\dfrac{1}{2}\le\dfrac{1}{2}\)

Dấu ''='' xảy ra khi x = -1/5