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

[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

 

[SammyS]

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

The Attempt at a Solution

Factor the numerator.

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

 

[jbunniii]

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

 

[surferbarney0729]

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

 

[HallsofIvy]

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.

 

[surferbarney0729]

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