Find all real solutions of the equation by completing the square. (enter your answers as a comma-separated list.) x2 − 4x − 8 = 0

After completing the square the expression is (x-2)^2 -12 =0 and real solution are x = 5.46 and x = -1.46

Step-by-step explanation:

We need to complete the square:

x^2 − 4x − 8 = 0

x^2 -2(x)(2)+(2)^2 -8 -4 =0

(x^2 -4x +4) - 12 = 0

(x-2)^2 -12 =0

Now, finding the value of x

(x-2)^2 -12 =0

(x-2)^2 = 12

taking square root on both sides

So, After completing the square the expression is (x-2)^2 -12 =0 and real solution are x = 5.46 and x = -1.46

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.