To find the x-intercepts of the function f(x) = 2x2 + 3x – 20, we need to determine the points where the graph of the function intersects the x-axis. This occurs when the value of the function is equal to zero.
So, we set the function equal to zero:
2x2 + 3x - 20 = 0
This is a quadratic equation in the form of ax2 + bx + c = 0, where:
- a = 2
- b = 3
- c = -20
To solve for x, we can use the quadratic formula:
x = (-b ± √(b2 - 4ac)) / 2a
Plugging in our values:
x = (-(3) ± √((3)2 - 4(2)(-20))) / (2(2))
Now, calculate the discriminant:
b2 - 4ac = 32 - 4(2)(-20) = 9 + 160 = 169
Now, we can substitute back to find the x-intercepts:
x = (-3 ± √169) / 4
This simplifies to:
x = (-3 ± 13) / 4
We will now calculate both possible values for x:
- x = (-3 + 13) / 4 = 10 / 4 = 2.5
- x = (-3 – 13) / 4 = -16 / 4 = -4
Thus, the x-intercepts of the function are:
- (2.5, 0)
- (-4, 0)
In conclusion, the x-intercepts of the function f(x) = 2x2 + 3x – 20 are (2.5, 0) and (-4, 0).