Question

lim x--->a

x^2+a^2/x+a

I know this equals (a) but I don't know how to explain my answer.

Answer 1

The first thing you should always do in limit problems is to substitute the approach value into the expression.
If you get a real number answer, you are done!

so if x = a
(a^2 + a^2)/(a+a)
= 2a^2/(2a)
= a

Limits only cause problems when
both numerators and denominators are zero
or something becomes undefined

Answer 2

Thanks! Exactly what I was looking for.