Question

find the x intercepts of f(x)=((x^2)+2x-24)/((x^2)+8x+12)

Answer 1

\[f(x)=\frac{ x ^{2}+2x-24 }{ x ^{2}+8x+12 }\]

Answer 2

I have already found x=-6 and x=4, but that was somehow wrong. Is one of these invalid for some reason?

Answer 3

the x = 4 is correct, the other x intercept however is x = 0 :)

Answer 4

@plohrb why isn't x=-6 correct?

Answer 5

you must have made a mistake somewhere, all you do is sub 0 for y and solve

Answer 6

im trying to find out where you could have

Answer 7

guess what

i guess you factored ot the quadratic equations right ?

we have to find two numbers when we multiply them we should get `product of AC`(a = leading coefficient , c= constant term)
when we add or subtract them we should get the middle term

Answer 8

I set the numerator equal to 0, is that wrong?

Answer 9

-6 times 4 = 24 \(\checkmark\)
-6+4 isn't positive 2

Answer 10

youre supposed to set the y equal to 0, not the numerator

Answer 11

x-intercepts a point where graph intersect x-axis when y = 0
so substitute y for 0
find factors of the numerator and denominator

Answer 12

if you set y equal to 0 then the denominator ends up getting multiplied by 0 anyways so its the same thing as setting the numerator to 0

Answer 13

if you multiply denominator by 0 then answer would be undefined
anything times 0 would be 0 and you can't divide by 0