Posted by **Kay** on Thursday, October 15, 2009 at 8:26pm.

Evaluate the limit at t --> 25: [25 - t] / [5 - √(t)]

I multiplied it by √(x + 3) to get rid of the square root on the bottom. However, once I'm done distributing it out, I'm not sure I'm doing it right.

I get [x√(x+3) + 2x - 2] / [x + 5]

Once I plug in 25 for t, I get really big numbers and I end up getting an off number that is not correct (like 25√28 + 48 / 30)

Can someone please help?

- Calculus: limits -
**Ian**, Thursday, October 15, 2009 at 8:35pm
Factor (25-t) into (5-sqrt(t)) and (5+sqrt(t))

Cancel top and bottom (5-sqrt(t) and left with lim t->25 of (5+sqrt(t))

which is 10.

- Calculus: limits -
**MathMate**, Thursday, October 15, 2009 at 8:36pm
The idea of rationalizing the denominator is excellent.

You may note that the denominator is of the form (A-B), so if you multiply top and bottom by (A+B), you will get (A²-B²) in the denominator.

Since you are taking the limit, t does not equal 25, so you are allowed to divide top and bottom by (25-t). Simplify and get a neat answer in no time.

## Answer this Question

## Related Questions

- Math(I Don't Get THIS!!) - 15sqrt8x^16/5sqrt2x^4 *I totally need help with this ...
- Math - Find an equation of the line that bisects the obtuse angles formed by the...
- Algebra 1 - Simplifying Radicals, Use the quotient property to simplify the ...
- MATH PLEASE CHECK IT!!2 - sqrt2/sqrt10 here is what I got: sqrt (2/10)= sqrt (1/...
- Algebra 2 Answer Check - Simplify by rationalizing each denominator. 1. 2/√...
- Algebra - How would i complete these problems? 1. (√6mn)^5 2. ^3√16x...
- Math - Just for reference √ = square root Evaluate the following ...
- Math - I need help simplifying radicals. The problem in priticular is the square...
- maths - I will be thankfull to you if you help me to solve the below problem: 6...
- Math - I need someone to check my homework answers. I don't really know this ...