Approximate Δ y using differentials for y = x2 – 4x at x = 6 when Δ x= dx = 0.03. Okay, what does Δ mean?

Question

Approximate Δ y using differentials for y = x2 – 4x at x = 6 when Δ x= dx = 0.03.  Okay, what does Δ  mean?

anonymous · Answer

The greek letter "delta", in mathematics and many sciences, it is used to express a change in a variable. In this case, the change in y, and the change in x.

anonymous · Answer

so does it mean the change in x when or change in y when you take the differential?

anonymous · Answer

does it want me to plug 6 into the un-differentiated problem and then again in the derivatives?

anonymous · Answer

$$
\Delta y\approx dy=y'dx
$$

anonymous · Answer

In this case $\Delta x=dx$

anonymous · Answer

ah okay.  thats given so its just derivative multiplied by that given value

anonymous · Answer

$dy$ is a linear approximation in the change of $y$.

anonymous · Answer

Whereas $\Delta y$ is the exact change of $y$.

anonymous · Answer

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