Question

Let f(x) = x^(4/3) - 7 x^(-8/3)

f '(x) = A xB + C xD, where

I think they want me to find a,b,c & d

Answer 1

I think I use the
power rule

Answer 2

exactly, and what dd you get?

Answer 3

f(x)= rx^r-1

Answer 4

and I get ...

Answer 5

4/3x^1/3- -56/3x^-3/2 is that right?

Answer 6

first term is right, but not the second
what is\[-\frac83-1\]?

Answer 7

-7/3

Answer 8

\[-\frac83-1=-\frac83-\frac33=-\frac{11}3\]which is your exponent on the second term

Answer 9

so 4/3x^1/3- -56x^-11/3

Answer 10

negative times negative is positive
we never write --
and you forgot to divide 56/3 in your final answer

Answer 11

oh yeah thanks didnt see that

Answer 12

wait something is wrong 56x^11/3

Answer 13

i mean 56x^-11/3

Answer 14

(56/3)x^(-11/3)

Answer 15

man I need to be careful

Answer 16

-7x^(-8/3)
-7(-8/3)x^(-8/3-1)
56/3x^(-11/3)
yeah, algebra can get you if you're not paying attention :P