# Derive equation with a multiplier and constant

1. Oct 26, 2013

### TMonkey

Hi there,

I'm trying to derive the following equation, but despite internet searching haven't been able to figure out what to do with the multiplier, D.

D * dθ/dz + k = C

I need to derive the equation and then plot the graph θ(y-axis) against z (x-axis).

Any help greatly appreciated,
thank you.

2. Oct 26, 2013

### vanhees71

Deriving from what? It helps a lot to clearly state the problem not only to be able to get help from others but also to solve the problem yourself!

3. Oct 26, 2013

### UltrafastPED

Derive the equation from what? Is it from raw data, or from a description of a property of something?

You would do better to look through your assignment and class notes rather than the internet! Or form a study group.

4. Oct 29, 2013

### HallsofIvy

Staff Emeritus
If by "derive the equation" you mean solve that equation for $\theta$ as a function of z just solve for $d\theta= [(C- k)/D]dz$. If C, k, and D are constants that gives $\theta= [(C- k)/D]z+ E$ where E is a "constant of integration".