Thread: differential help.

Hello,

Hopefully someone can help me...


Let .
Find the differential when and
Find the differential when and

this is a new concept for me, any help is greatly appreciated. Thanks!

Originally Posted by xcelxp

Hello,

Hopefully someone can help me...


Let .
Find the differential when and
Find the differential when and

this is a new concept for me, any help is greatly appreciated. Thanks!

Let's differntiate:

y = 2x^2 + 2x + 4
=> dy/dx = 4x + 2
=> dy = dx(4x + 2)...........multiplied both sides by dx

when x = 1 and dx = 0.3
=> dy = 0.3(4(1) + 2)
=> dy = 1.8

when x = 1 and dx = 0.6
=> dy = 0.6(4(1) + 2)
=> dy = 3.6

the trick is that dy/dx is more than just a notation, we can treat it like a fraction and split it up, so we are able to solve for one piece of it

Thanks!