How do you solve x^2>=36x236 using a sign chart?

1 Answer
Aug 3, 2016

x in(oo,-6]uu[6,oo)x(,6][6,)

Explanation:

x^2>=36x236

Let us take the equation first .

x^2=36x2=36

x=+-6x=±6

Divide the number line into 3 parts , use this x valuesenter image source here
Check which interval satisfies the inequality x^2>=36x236
In the interval (-oo,-6) (,6) choose a point say x=-7
x^2=49 so x^2>=36#

In the interval (-6,6) , x=0,x^2=0 , x^2<36(6,6),x=0,x2=0,x2<36
in the interval (6,oo) , x=7 , (6,),x=7,x^2=49 , x^2>=36x236
enter image source here

First and 3rd interval satisfies the inequality . we have >=

x in(oo,-6]uu[6,oo)x(,6][6,)