# Math Help - How to find the intercepts of y=x^3-3x

1. ## How to find the intercepts of y=x^3-3x

How to find the intercepts of y=x^3-3x. I keep coming up with x intercept= (sq.rt. 1, 0) and y intercept (0,0) but was told a part of that answer or the whole thing is wrong or it is incomplete.

2. ## Re: How to find the intercepts of y=x^3-3x

Originally Posted by kmerr98277
How to find the intercepts of y=x^3-3x. I keep coming up with x intercept= (sq.rt. 1, 0) and y intercept (0,0) but was told a part of that answer or the whole thing is wrong or it is incomplete.
There are three x-intercepts. Solve $x(x^2-3)=0~.$

3. ## Re: How to find the intercepts of y=x^3-3x

(x^2-3) factors to (x-3) and (x-1). so...x intercepts are (3,0) and (-1,0)?

4. ## Re: How to find the intercepts of y=x^3-3x

Originally Posted by kmerr98277
(x^2-3) factors to (x-3) and (x-1).
No it does not factor that way.

$(x^2-3)=(x-\sqrt3)(x+\sqrt3)$

5. ## Re: How to find the intercepts of y=x^3-3x

so... x intercepts are (sq.rt.3,0) and (-sq.rt.3, 0) and i have no idea about the third intercept. How do you enter symbols into the forum? Thanks a lot!!

6. ## Re: How to find the intercepts of y=x^3-3x

Originally Posted by kmerr98277
i have no idea about the third intercept. How do you enter symbols into the forum?
The third is $(0,0)$

[TEX](x-\sqrt{3})(x+\sqrt{3})[/TEX] gives $(x-\sqrt{3})(x+\sqrt{3})$