I'm doing a related rates problem. The equation is:
y = (3/5)x
I need dx/dt. So, that could be written as:
dx/dt = dx/dy * dy/dt
Would the appropriate way to do this be:
d/dy(y) = d/dy(3x/5)
1 = (3/5)*(dx/dy)
And then solve for dx/dy and do the substitution?

My concern is that taking the implicit derrivative with respect to y might be...abnormal? It makes the most sense in my mind, but I see a lot of examples where you take it with respect to t and then use the chain rule for both x and y. (I can try to clarify if this doesn't make sense.)

Question

I'm doing a related rates problem. The equation is: 
y = (3/5)x
I need dx/dt. So, that could be written as:
dx/dt = dx/dy * dy/dt
Would the appropriate way to do this be:
d/dy(y) = d/dy(3x/5)
1 = (3/5)*(dx/dy)
And then solve for dx/dy and do the substitution?

My concern is that taking the implicit derrivative with respect to y might be...abnormal? It makes the most sense in my mind, but I see a lot of examples where you take it with respect to t and then use the chain rule for both x and y. (I can try to clarify if this doesn't make sense.)

zepdrix · Answer

|dw:1348978352263:dw|
Not sure why you would go it with respects to y first hmm