SOLUTION: When the parabola: {{{y = x^2-a(x+1)+3}}} intersects the x-axis at one point, then a must equal ___ or ___. What I've got so far, (not a lot unfortunately): {{{y = 0}}} {

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: When the parabola: {{{y = x^2-a(x+1)+3}}} intersects the x-axis at one point, then a must equal ___ or ___. What I've got so far, (not a lot unfortunately): {{{y = 0}}} {      Log On


   

Question 146209: When the parabola: y+=+x%5E2-a%28x%2B1%29%2B3 intersects the x-axis at one point, then a must equal ___ or ___.
What I've got so far, (not a lot unfortunately):
y+=+0
0+=+x%5E2-a%28x%2B1%29%2B3
a+=+%28x%5E2%2B3%29%2F%28x%2B1%29
and here I become unstuck. No use of graphics calculator permitted. Much thanks for any help!


Answer by oscargut(2103) About Me  (Show Source):
You can put this solution on YOUR website!
the parabola: intersects the x-axis at one point,so
(-a)^2-4(1)(3)=0 so a^2-12=0 so a=sqrt%28+12+%29 ora=-sqrt%28+12+%29