What is the domain of 2x2+x6?

1 Answer
Jan 3, 2017

The domain is x],2][32,[

Explanation:

We factorise

2x2+x6=(2x3)(x+2)

Then,

2x2+x60

(2x3)(x+2)0

Let f(x)=(2x3)(x+2)

We have to do a sign chart

aaaaxaaaaaaaa2aaaaa32aaaa+

aaaax+2aaaaaaaaaa+aaaaa+

aaaa2x3aaaaaaaaaaaaaa+

aaaaf(x)aaaaaaa+aaaaaaaaa+

Therefore,

As f(x)0

The domain is x],2][32,[