Question

Find the zeros of the function algebraically

f(x)=9x^2-3x-2

Please explain step by step

Answer 1

Step 1. Use quadratic formula.
Step 2. Go get a snack.

Answer 2

(You can omit step 2 if you want)

Answer 3

Lol

Answer 4

Could also be factored . . .

Answer 5

factored?

Answer 6

that's what I've been doing. I just don't know what to do with the 9x^2

Answer 7

Yes like (2x+1)(x-3) = 2x^2-5x-3,
(2x+1)(x-3) is the factored form of 2x^2-5x-3.

Answer 8

okay, so that would make the 9x^2 go to (3x ) (3x ) ?

Answer 9

Most likely. Recall that when you multiply two binomials, (ax+b)(cx+d) = acx^2+adx+bcx+bd.

Answer 10

In your case a*c=9, and b*d=-2.
You need to find a,b,c, and d such that ac=9, bd=-2 and ad+bc=-3

Answer 11

sooo, it would come out to (3x-2) (3x+1) right?

Answer 12

That looks right, so now you set each of those factors =0 to find the roots.