Question

Find numbers a and b such that lim x->0 (\[\sqrt{ax+b}\]-2) / x = 1

Answer 1

Multiply top and bottom by:\[\sqrt{ax+b}+2\]

Answer 2

I did. I got (ax+b-4) / (x (\[\sqrt{ax+b}\] + 2) but can;t figure a way to factor from there.