Find the x-intercepts of the quadratic function c(x) = 2x^2 + x - 10.
Check the final answer first, then review the worked steps.
Check the final answer first, then review the worked steps.
3. Solve the quadratic equation: We can solve this quadratic equation using the quadratic formula, which is $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.
Substitute the values of $a$, $b$, and $c$ into the formula:
$$x = \frac{-1 \pm \sqrt{1^2 - 4(2)(-10)}}{2(2)}$$
4. Calculate the discriminant: First, calculate the value inside the square root (the discriminant):
$$1^2 - 4(2)(-10) = 1 - (-80) = 1 + 80 = 81$$
5. Continue solving for x: Now substitute the discriminant back into the quadratic formula:
$$x = \frac{-1 \pm \sqrt{81}}{4}$$
$$x = \frac{-1 \pm 9}{4}$$
6. Find the two x-intercepts: We have two possible values for $x$ because of the $\pm$ sign:
For the '+' sign:
$$x_1 = \frac{-1 + 9}{4} = \frac{8}{4} = 2$$
For the '-' sign:
$$x_2 = \frac{-1 - 9}{4} = \frac{-10}{4} = -\frac{5}{2}$$