$\"\"$

The linearity fucntion is $\"\"$

The rate of change in $\"\"$ is $\"\"$ constant.

$\"\"$

Differentiate on each side with respect to $\"\"$ .

$\"\"$ .

Substitute $\"\"$ in the derivative function.

$\"\"$

Since $\"\"$ is constant .The value of $\"\"$ is also constant with a variable $\"\"$ .

$\"\"$

The value of $\"\"$ is also constant with a variable $\"\"$ .