SOLUTION: If the graph of the parabola y=kx^2+6x+k+8 is tangent to x-axis, then what is the positive value of k?

Algebra ->  Functions -> SOLUTION: If the graph of the parabola y=kx^2+6x+k+8 is tangent to x-axis, then what is the positive value of k?      Log On


   

Question 167267: If the graph of the parabola y=kx^2+6x+k+8 is tangent to x-axis, then what is the positive value of k?
Answer by oscargut(2103) About Me  (Show Source):
You can put this solution on YOUR website!
if the graph is tangent to x-axis then discriminant is 0
then b%5E2-4ac=0
then
6%5E2-4%28k%29%28k%2B8%29=0
36-4k%5E2-32k=0
-4k%5E2-32k%2B36=0
k%5E2%2B8x-9=0
then k=1 or k=-9
then k=1 (positive value)
Answer: k=1