This is a problem from a Calc 1 text book, I just can't figure out where they get dx from. The question is:(adsbygoogle = window.adsbygoogle || []).push({});

Use differentials to approximate the value of the expresesion.

[tex]\sqrt{99.4}[/tex]

the answer in the solution manual says:

Let [tex]f(x)=\sqrt{x}, x=100, dx=-.6[/tex]

then it solves the problem. But what I don't understand is where the heck is this dx quantity derived from?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Simple Differential Problem

**Physics Forums | Science Articles, Homework Help, Discussion**