# How do you simplify and find the excluded value of #(x^2+x+1)/(1-x^2)#?

##### 1 Answer

Apr 26, 2017

see explanation.

#### Explanation:

Factorise the denominator using the

#color(blue)"difference of squares"#

#(x^2+x+1)/((1-x)(1+x))# The denominator of the function cannot equal zero as this would make it

#color(blue)"undefined".# Equating the denominator to zero and solving gives the values that x cannot be.

#"solve " (1-x)(1+x)=0#

#rArrx=1" or " x=-1larrcolor(red)" excluded values"#