for quadratic function f, the solutions to the equation f(x) = 0 are x = 8 and x = -4. which function could represent f. Answer using these choices: a. f(x) = x^2 + 4x - 32

b. f(x) = x^2 + 12x + 32
c. f(x) = x^2 - 4x - 32
d. f(x) = x^2 - 12x + 32

1 answer

Given that the solutions to the equation f(x)=0 are x=8 and x=4, we can start by expressing the quadratic function in its factored form. The factored form is given by:

f(x)=a(xr1)(xr2)

where r1 and r2 are the roots. In this case, r1=8 and r2=4. Thus, we can express the function as:

f(x)=a(x8)(x+4)

To find a specific quadratic function, we can expand this:

f(x)=a[(x8)(x+4)]=a[x2+4x8x32]=a[x24x32]

Now, we can compare the general form f(x)=ax24ax32a to each of the choices provided. We see that:

  1. In f(x)=x2+4x32:

    • a=1, b=4 (not matching since b=4a)
  2. In f(x)=x2+12x+32:

    • a=1, b=12 (not matching)
  3. In f(x)=x24x32:

    • a=1, b=4 (matches since b=4a)
  4. In f(x)=x212x+32:

    • a=1, b=12 (not matching)

The correct choice that matches our derived quadratic function is:

c.,f(x)=x24x32