general question about differentiating

purebladeknight · #1 $Old$ November 4th, 2009, 10:56 PM

hi, a question asks "find the derivatives with respect to x of the following"
they are given in a form without y. e.g -3sin(3x) or 1/(3e^(3x))

can i assume them to be y= .... e.g y=-3sin(3x) when differentiating or must i state: let y=........ and then differentiate that.

HallsofIvy · #2 $Old$ November 5th, 2009, 04:37 AM

Use whatever form you are used to- it really doesn't matter whether you call it " $\frac{dy}{dx}$ " or " $\frac{df}{dx}$ " or call the function by any other name. A function by any other name differentiates as good!