contestada

The function f(x) = x^2 +8x+10 is equivalent to the function f(x)=(x-h)^2+k. What is the value of h and k . At what value of x is the minimum value of the function

Respuesta :

ANSWER

[tex]h = - 4,k = - 6[/tex]

Minimum value: y=-6

Occurs at: x=-4

EXPLANATION

Given

[tex]f(x) = {x}^{2} + 8x + 10[/tex]

We need to write the equivalent of this function in vertex form:

[tex]f(x) = ({x - h)}^{2} + k[/tex]

where (h,k) is the vertex.

We must complete the square to get the function to this form.

We add and subtract the square of half the coefficient of x.

[tex]f(x) = {x}^{2} + 8x +( \frac{8}{2}) ^{2} - ( \frac{8}{2}) ^{2} + 10[/tex]

This gives us;

[tex]f(x) = {x}^{2} + 8x +16- 16 + 10[/tex]

The first three terms form a perfect square quadratic trinomial.

[tex]f(x) =( x + 4) ^{2} - 6[/tex]

or

[tex]f(x) =( x - - 4) ^{2} - 6[/tex]

Therefore we compare to

[tex]f(x) = ({x - h)}^{2} + k[/tex]

h=-4 and k=-6

The minimum value of the function is

[tex]y = - 6[/tex]

and this occurs at;

[tex]x = - 4[/tex]