# Homework Help: Find the Limit, if it exists.limx→ 2 x^2+7x-18

1. Jul 17, 2012

### surferbarney0729

Find the Limit, if it exists.limx→ 2x^2+7x-18

Find the Limit, if it exists.

lim
x→ 2

x^2+7x-18
x-2

I know the answer is 11, but I am confusing myself on how 11 became the answer. My textbook is worthless and I need a dumbed down reason as to how 11 became the answer.

Thanks
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jul 17, 2012

### SammyS

Staff Emeritus
Re: Limits

Factor the numerator.

According to the rules of this Forum, you need to show some effort before we can give much help.

3. Jul 17, 2012

### jbunniii

Re: Limits

I suggest that you start by factoring the polynomial in the numerator. This should be easy because ___ is a root (fill in the blank).

4. Jul 17, 2012

### surferbarney0729

Re: Limits

My mistake, I should have not over thought that one.

factor the polynomial is what I was missing for some reason

(x+9)(x-2),

(x-2)'s factor and

(2+9) is how 11 is formed

5. Jul 17, 2012

### HallsofIvy

Re: Limits

You mean the (x- 2)'s cancel, not "factor". And that is true as long as x is NOT 2. Fortunately, the limit, as x approaches 2, is not dependent upon the value at x= 2.

6. Jul 17, 2012

### surferbarney0729

Re: Limits

Thanks for all your help. Pardon my mistakes in wording. I do know the difference in how things are worded is vital to the cumulative world of higher math. I am teaching myself calculus through a textbook and some e-calculus website in hopes of getting familiar with it before entering college again after 8 years in the Marines.

Love the help and the website.

Thanks again