## Functions Defined By Equations: solve f(x) = 0 for f(x) = x^

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.
sk8rgirl130
Posts: 2
Joined: Fri May 01, 2009 6:41 pm

### Functions Defined By Equations: solve f(x) = 0 for f(x) = x^

For each function, (a) find f(0), and (b) solve f(x) = 0
f(x) = x^2 - 13x + 40

I completed (a) and got f(x) = 40.

I need help figuring out (b)

stapel_eliz
Posts: 1628
Joined: Mon Dec 08, 2008 4:22 pm
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For each function, (a) find f(0), and (b) solve f(x) = 0
f(x) = x^2 - 13x + 40

I need help figuring out (b)
Plug "0" in for "f(x)" to get:

. . . . .0 = x2 - 13x + 40

Then solve the quadratic equation by whatever method you prefer. You could solve by factoring, since x2 - 13x + 40 = (x - 5)(x - 8), or you could always use the Quadratic Formula.

sk8rgirl130
Posts: 2
Joined: Fri May 01, 2009 6:41 pm

### Re: Functions Defined By Equations: solve f(x) = 0 for f(x) = x^

thanks soooo much. i cant believe i couldnt remember to do that. i guess it was just a hard day. thanks sooo much. i appreciate it.