Thread: Limit question

Hello,

I think the question is simple but not sure if this would be correct. I have a limit that is:
lim x²-25
______
x->2 sqrt (2x+6) -4

Now the bottom would be root 10 - 4, so I don't think I need to multiply it by root 10 +4 to get rid of it so is that fine?
x could not be 5

Thanks!

Correct, you dont need to multiply through by the conjugate.

Thanks... I felt like that was a trick question or something because normally in other questions that is what you do. So you don't always have to conjugate then

No, in your case substituting the value is fine.

Originally Posted by funnybabe

Hello,

I think the question is simple but not sure if this would be correct. I have a limit that is:
lim x²-25
______
x->2 sqrt (2x+6) -4

Now the bottom would be root 10 - 4, so I don't think I need to multiply it by root 10 +4 to get rid of it so is that fine?
x could not be 5

Thanks!

If a function is continuous at the point you are making the function approach, then the limit is equal to the function value at that point.