How do you solve x^2-4<=0x240?

1 Answer
Aug 30, 2016

-2 ≤ x ≤22x2

Explanation:

Write as a quadratic equation and solve, and then select test points.

x^2 - 4 =0 x24=0

(x + 2)(x - 2) = 0(x+2)(x2)=0

x = -2 and 2x=2and2

Usually, we choose one point inside the parabola and another outside

The x-intercepts of the parabola are x = +-2x=±2, so let the test point on the exterior be x = -4x=4 and the point on the interior be x = 1x=1.

Test point 1: x = -4x=4

-4^2 - 4 <=^?0424?0

12 cancel(<=) 0

Hence, by deduction, the interval of solution is -2 ≤ x ≤ 2. Or, in other words, the inside of the parabola is shaded.

Hopefully this helps!