SOLUTION: what are the intercepts in this problem x^2 + x -2

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: what are the intercepts in this problem x^2 + x -2      Log On


   

Question 9336: what are the intercepts in this problem
x^2 + x -2
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
First, before you can have intercepts, you have to have the equation for a graph. Do you mean find the intercepts for +y+=+x%5E2+%2Bx+-+2

If so, then the y intercept is always where x=0. If x = 0, then y = -2. That's the y-intercept.

The x-intercept is always where y = 0. If y=0, this means that
0+=+x%5E2+%2B+x+-2 which is a quadratic equation. (See my Lesson Plan on Solving Quadratic Equations and also Factoring Trinomials.) This quadratic equation can be solved by factoring.

+0+=+x%5E2+%2B+x+-2
+0+=+%28x%2B2%29%28x-1%29+

Set each factor equal to zero:
x+2 = 0
x= -2

x-1 = 0
x=1

Therefore, x = -2 and x= 1 are the x-intercepts.

R^2 at SCC