SOLUTION: I'm having truble here...apply the quadratic formula to find the roots of the given function, and then graph the function. f(x) = x^2 + 4

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I'm having truble here...apply the quadratic formula to find the roots of the given function, and then graph the function. f(x) = x^2 + 4      Log On


   

Question 36335: I'm having truble here...apply the quadratic formula to find the roots of the given function, and then graph the function.
f(x) = x^2 + 4
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve f%28x%29+=+x%5E2%2B4 by the quadratic formula:x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a
If you write your equation in the standard form:ax%5E2%2Bbx%2Bc=0 you will see that a = 1, b = 0, and c = 4, so applying the quadratic formula:
x+=+%28-0%2B-sqrt%280%5E2-4%281%29%284%29%29%29%2F2%281%29
x+=+%28-0%2B-sqrt%28-16%29%29%2F2
x+=+4sqrt%28-1%29%2F2 and x+=+-4sqrt%28-1%29%2F2
x+=+2sqrt%28-1%29 and x+=+-2sqrt%28-1%29 Simplify. sqrt%28-1%29+=+i
x+=+2i and x+=+-2i These are the roots.
The graph:
graph%28300%2C200%2C-5%2C5%2C-5%2C10%2Cx%5E2%2B4%29