I have about 10 of these problems I could post, can't figure any of them out...not sure what to do.
$\lim_{h \to 0}\dfrac{(\sqrt{9+h} -3)}{h}$
I know that I need to rationalize it so I multiply by the numerator which gives me
$9 + h - 9$ (not sure if positive or negative since it is $-3$ squared it should be $9$ but it could also be minus square of $3$ which would be -9 /h sqr(9+h) -3
From that I can divide by h and get 1/3-3
which I know is wrong. What am I doing wrong?