Calculus Course/Change in Variable

Change in Variable

A Change in variable is a term used to express the difference between 2 variables . Let $\mathrm{\Delta }$ represents Change in 2 variables $x_0$ and $x$ then

$\mathrm{\Delta }x=x-x_0$

$x=x_0+\mathrm{\Delta }x$

If there is a function $f(x)$ such that when $x$ change by an amount $\mathrm{\Delta }x$ the change in function will be

$\mathrm{\Delta }f(x)=f(x)-f(x_0)$

$f(x)=f(x_0)+\mathrm{\Delta }f(x)$

Example

There are 2 points (1,3) (5,7) then

$\mathrm{\Delta }x=x-x_0=5-1=4$

$\mathrm{\Delta }f(x)=7-3=4$