Question

Find dy/dx if y = sin (x+y)?

Here's my work, but I think it's wrong...
d/dx [y] = d/dx [sin (x+y)]
dy/dx = cos (x+y) * d/dx (x+y)

Please help...

Answer 1

Nothing wrong in your answer, you just didn't finish yet. Find d/dx (x+y).

Answer 2

dy/dx (x+y) = (1+1) = 2?
So... would it be dy/dx = 2 cos (x+y)? wait... that's not one of the answer choices :'(
Help me out here, please?

Answer 3

d/dx (x+y) = 1

Answer 4

\[\frac{ d }{ dx } (x + y) = 1 + \frac{ dy }{ dx }\]

Answer 5

Sorry my bad ! @niksva is right.

Answer 6

Thank you guys! So dy/dx = cos (x+y) * 1+dy/dx... and do I move 1+dy/dx to the left?

Answer 7

You distribute first dy/dx=cos(x+y)+cos(x+y)*dy/dx.
Then yeah you move cos(x+y)*dy/dx. to the left.

Answer 8

I think I got it...! Is the answer dy/dx = cos (x+y) / 1-cos (x+y)??

Answer 9

That's right !

Answer 10

Ah, finally! Thanks so much!!!! :) :) To niksva too! :)

Answer 11

Your welcome

Answer 12

pleasure :-P