i'm so confuse with this problem I have to use the limits rules but find the derivative B. F (x)= x²-16/x-4=?

Question

i'm so confuse with this problem I have to use the limits rules but find the derivative B.	F (x)= x²-16/x-4=?

jdoe0001 · Answer

hmm, well, that's an easy one :/

jdoe0001 · Answer

notice $\bf x^2-16\
\text{keep in mind that}\
(a-b)(a+b) = (a^2-b^2)
$

anonymous · Answer

-15?

anonymous · Answer

i think i have to subtract but i don't really remember the derivative rules :s

jdoe0001 · Answer

well, you want the derivative of f(x) right?

anonymous · Answer

yes

jdoe0001 · Answer

so  $\bf \cfrac{x^2-16}{x-4}\
\cfrac{x^2-4^2}{x-4} \implies \cfrac{\cancel{(x-4)}(x+4)}{\cancel{x-4}}\
x+4$

jdoe0001 · Answer

from there just use the power rule to get the derivative of x+4

anonymous · Answer

O_o wow lol u made it look so easy.... hehehe thanks

jdoe0001 · Answer

yw

jdoe0001 · Answer

so using the power rule, derivative of $\bf x^{1}$  is 1, and 4 is a constant so derivative of a constant is 0, so
1 + 0 => 1

anonymous · Answer

-_- goodness I found this site (y) @jdoe0001