Question

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

Answer 1

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

Explanation:

`x^2>=36`

Let us take the equation first .

`x^2=36`

`x=+-6`

Divide the number line into 3 parts , use this x values
Check which interval satisfies the inequality `x^2>=36`
In the interval `(-oo,-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`
in the interval `(6,oo) , x=7 ,`x^2=49 , `x^2>=36`

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

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