Question

Consider the graph of the function y=1/4x2-3x-40. what are the roots of the function?

Answer 1

Answer: the roots are x = 20 and x = -8

Explanation:

We have the function

y = (1/4)x^2 - 3x - 40

We want to find the roots, that are the points in where y(x) = 0

For a quadratic equation of the form:

y = a*x^2 + bx + c the roots are:

`x = (-b +-√(b^2 -4*a*c) )/(2*a)`

in this case we have:

`x = (3 +-√(3^2 +4*(1/4)*40) )/(2*(1/4))= (3 +-7)/((1/2))`

So the two roots are:

x = 2*(3 + 7) = 20

x = 2*(3 - 7) = -8