- #1
throneoo
- 126
- 2
Homework Statement
http://www5b.wolframalpha.com/Calculate/MSP/MSP19531i2efadg8b4hce2f00000hb7532fcd20a6h7?MSPStoreType=image/gif&s=47&w=253.&h=47.
basically I have to evaluate the limit on LHS , the above image is from wolfram alpha . (if link doesn't work , it's
limit of (x^3)*((x^2-1)^-0.5-(x^2+1)^-0.5) as x->infinity)
2. The attempt at a solution
L'hopital's rule wouldn't work, as x^3 vanishes after the 3rd derivative , but (x^2+a)^0.5 would not terminate at higher derivatives and I can't find the limit at their 1st and 2nd derivatives.
I've tried to change variables such as letting u=(x^2-1)^0.5 but that failed as well , and taylor expansion wouldn't help as it's an infinite series .
now I seem to be running out of methods .
I will appreciate any suggestion for an approach
Last edited by a moderator: