I have to find in terms of the constant a. Please try and explain for me, it seems easy but I keep putting the wrong answer.
lim h-> 0 (6/a+h)-(6/a) / h
lim h-> 0 (6/a+h)-(6/a) / h
-
lim h->0 [(6a-6a-6h)/((a+h)a)] / h
lim h->0 [-6h/((a+h)a)] / h
= -6/a^2
Explanation: step 1: get a common denominator for the fractions on the top. remember to distribute the (-) when doing so.
step 2: cancel out the terms you can, like the +6a and -6a.
Step3: cancel out the h's you can. the h in -6h and the bottom h can cancel out. plug in 0 for the other h in the ((a+h)a) section.
step 4: simplify and you have your derivative.
lim h->0 [-6h/((a+h)a)] / h
= -6/a^2
Explanation: step 1: get a common denominator for the fractions on the top. remember to distribute the (-) when doing so.
step 2: cancel out the terms you can, like the +6a and -6a.
Step3: cancel out the h's you can. the h in -6h and the bottom h can cancel out. plug in 0 for the other h in the ((a+h)a) section.
step 4: simplify and you have your derivative.