Question

Let y= 3x^2 + 6x +2
Find the differential dy when x=5 and dx= 0.3
Find the differential dy when x=5 and dx= 0.6

Answer 1

dy= 6x dx + 6 dx
now plug in values for x and dx

Answer 2

oh now i get it you set it up as a proportion....

Answer 3

dy/dx = (6x+6)/.3 right?

Answer 4

normally we think of dx as an infinitesimal, but here they are not.

Answer 5

I think it is
dy/dx = 6x+6

or dy= (6x+6) * dx

Answer 6

oh ok

Answer 7

oh i always forget to put the dx after i take a derivative

Answer 8

normally you put the dx in the denominator i.e. dy/dx = d f(x)
so the dx is on the left-hand side.

Answer 9

Thank you guys! :D