$\"\"$

Ohm $\"\"$ law : The voltage $\"\"$ applied to the resistor $\"\"$ is $\"\"$ , where $\"\"$ is the current passes through a resistor.

Consider $\"\"$ .

Solve for $\"\"$ .

$\"\"$ .

Differentiate the above equation with respect to $\"\"$ .

$\"\"$

Substitute $\"\"$ in $\"\"$ .

$\"\"$

Thus, the magnitude of the relative error in $\"\"$ caused by a change in $\"\"$ is equal in magnitude to the relative error in $\"\"$ .

$\"\"$

$\"\"$ .