What is the minimum value of g(x) = x^2+ 12x + 11?g(x)=x2+12x+11? on the interval [-5,0][5,0]?

1 Answer
Sep 24, 2017

Minimum value of g(x) = -24 g(x)=24 on the interval [-5,0][5,0]

Explanation:

g(x) = x^2+12x+11 :. g^'(x) = 2x+ 12 :. g^('')(x) =2.

Turning point :g^'(x)=0 or 2x =12=0 or x= -6

Since g^('')(x) =2 ; >0 . Turning point is the minimum point.

But x=-6 is beyond the interval [-5,0]. Since it is parabola

opening upwards, in the interval [-5,0] ; g(-5) will be of

minimum value , :. g(5) = (-5)^2+12*(-5)+11 = -24

i.e (-5,-24)

graph{x^2+12x+11 [-80, 80, -40, 40]} [Ans]