Question

Find Dxy of (photo)

Answer 1

I am confused about notation. It's the partial wrt x then wrt y?

Answer 2

@bmp I think it is asking for the derivative, look at photo

Answer 3

answer choices:

Answer 4

That is the problem: \( D_{xy} \) means partial wrt x then wrt y. But I guess you are right. What have you tried so far?

Answer 5

I got the first answer option by getting rid of the ^3

Answer 6

No, remember that derivative of x^n = n * x^(n-1). The ^3 shouldn't disappear, it should become a 2, right?

Answer 7

oh okay so then i would rearrange it 3(3x^3-3x^2)2

Answer 8

i mean )^2

Answer 9

Yup, but now, remember the chain rule? We have to take the derivative with respect to x of the inside out, that is, the answer should be \( 3(3x^3 - 3x^2)^2 \Large\frac{d(3x^3 - 3x^2)}{dx}\)

Answer 10

And those answer choices are quite lame, you have your answer without computing the inside derivative...

Answer 11

@bmp yea i know my teacher confuses me a ttimes, thankyou so much!

Answer 12

No problem. But did you understand why it wasn't only 3(3x^3 - 3x^2)^2?