I need help finding the x-intercept for this function:

f(x)=2x^2-5x-3/x^3-2x^2-x+2

Question

I need help finding the x-intercept for this function:

f(x)=2x^2-5x-3/x^3-2x^2-x+2

anonymous · Answer

I know the process...I'm just not really to sure about this problem

zepdrix · Answer

Hmm what is the process you use? :D
Maybe i can help if i know what method you're using.

anonymous · Answer

I factor the numerator function (2x^2-5x-3)...and then find the zeros for that

anonymous · Answer

but this one doesn't factor...unless I apply the quadratic formula...but then that gave me an imaginary number i think...im not very good at implementing imaginary numbers im afraid =/

zepdrix · Answer

Ohhh i didn't see the division in the middle :D i see what's going on, big ole fraction huh? :D ok lets see..

zepdrix · Answer

$$f(x)=\frac{ 2x^2-5x-3 }{ x^3-2x^2-x+2 }$$
So x-intercepts, we want to know when f(x)=0
So we can set the numerator = 0 since that is the same thing as setting the whole thing equal to 0.

$$0=2x^2-5x-3$$

$$x=\frac{ 5\pm \sqrt{25-4(2)(-3)} }{ 2(2) }$$
It doesn't look like you'll get any imaginary roots, are you setting it up correctly? :)

anonymous · Answer

woops i messed up haha...let me try once more

zepdrix · Answer

(x-3)(2x+1)=0

Hmm it looks like this one actually DOES factor, its sometimes difficult to see it though when you have a coefficient on the x^2 term. :O

anonymous · Answer

or im just really bad at factoring =/

anonymous · Answer

thanks for the help! =)