Engineering Handbook/Calculus/Change Variable

Change Variable

Let x be the integer variable then the change in variable x can be defined as

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

Therefore

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

if there is a function of x f(x) then a change in variable x causes a change in the function as

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

Then

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