- #1
QueenFisher
let f(x) = ln(x-2)+ln(x-6). Write down the natural domain of f(x).
i got this bit right, it's x>6
find f'(x)
i got 1/(x-2) + 1/(x-6)
which i think is right.
then it says find the intervals for which f'(x) is a. positive and then b. negative.
for a. i put f'(x)>0 and solved for x and i got the right answer, but I'm not sure if this is the right method.
because for b. if i put f'(x)<0 and solve for x i don't get the right answer.
can anyone help?:yuck:
i got this bit right, it's x>6
find f'(x)
i got 1/(x-2) + 1/(x-6)
which i think is right.
then it says find the intervals for which f'(x) is a. positive and then b. negative.
for a. i put f'(x)>0 and solved for x and i got the right answer, but I'm not sure if this is the right method.
because for b. if i put f'(x)<0 and solve for x i don't get the right answer.
can anyone help?:yuck: