Question

checking my answer: lim->5+ (3x)/(5-x). I think it's equal to -infinity

Answer 1

I found my answer by plugging in 5.1, 5.01, 5.001. Is there a better method?

Answer 2

assuming it's correct :)

Answer 3

This is how I usually do it.
And yes, your answer is correct.

When lim x->5+ f(x) = 3x/(5-x)
x approaches something slightly greater than 5
Thus, if we take any small, positive value 'h' approaching zero. Then x we can also say that x approaches 5+h.

Thus we can also write the limit like this

\[\lim_{h \rightarrow 0}~~~ [\frac{3(5+h)}{5-(5+h)}]\]

When you calculate that, you'll get infiniti.

Answer 4

ok cool, thanks :)

Answer 5

You're welcome. :)