Question

Determine f(x) = [(x-7)^9]/12 using the derivative rules. I don't get his question because the constant 12 in the denominator confuses me when using the product rule.. please help

Answer 1

just take it out.. its a constant u can ignore it and at the end add it again..

Answer 2

do it like 1/12 times derivative of the rest..

Answer 3

1/12 times 9(x-7)^8

Answer 4

(3/4)(x-7)^8

Answer 5

our teacher told us that we should put 12 as a negative exponent, so 12^(-1) and use the product rule.. :S

Answer 6

u can't do that... its not 12x is it?

Answer 7

You CAN do that, but it's not a good way to do it. Just remember that 12^(-1) is still a constant, so its derivative is 0.

Answer 8

The best bet with constant multipliers, like your 1/12, is to do as bahrom says -- hide the constant, take the derivative of what's left, then put the constant back.

Answer 9

Oh i see. But if I do 12^(-1), does it make a difference if I do (12)^(-1) or 12^(-1) when in the equation?

Answer 10

its the same thing but u wont use product rule for constants.. u probably copied the question wrong..

Answer 11

ANY DIFFERENTIATION RULES ARE FOR VARIABLES OR FUNCTIONS WITH VARIABLES...

Answer 12

this question was on the test and I got it wrong :( after we got it back, she told us that we should use the product rule so yeah..
thanks guys :)

Answer 13

Using product rule on 12^(-1) * (x - 7)^9 gives
0 * (x - 7)^9 + 12^(-1) * 9(x - 7)^8 (and then simplify).
It works, but why would you go to the extra trouble?