$\"\"$

The function $\"f\\left$ .

Find $\"\"$ $\"f\\left$ .

Substitute $\"x=a\"$ in $\"f\\left$ .

$\"f\\left$ .

$\"\"$

Find $\"f\\left$ .

Substitute $\"x=a+h\"$ in $\"f\\left$ .

$\"f\\left$

$\"f\\left$ .

$\"\"$

Find $\"\\frac{f\\left$ .

Substitute the values of $\"f\\left$ and $\"f\\left$ .

$\"\\frac{f\\left$

$\"=\\frac{a^2+h^2+2ah-6a-6h+8-a^2+6a-8}{h}\"$

$\"=\\frac{h^2+2ah-6h}{h}=\\frac{h(h+2a-6)}{h}\"$

$\"\\frac{f(a+h)-f(a)}{h}=h+2a-6\"$ .

$\"\"$

$\"f\\left$ .

$\"\\frac{f(a+h)-f(a)}{h}=h+2a-6\"$ .