Examples
f(x)=x2f(x)=x2 , x=0x=0
Step 1
Consider the difference quotient formula.
f(x+h)-f(x)hf(x+h)−f(x)h
Step 2
Step 2.1
Evaluate the function at x=x+hx=x+h.
Step 2.1.1
Replace the variable xx with x+hx+h in the expression.
f(x+h)=(x+h)2f(x+h)=(x+h)2
Step 2.1.2
Simplify the result.
Step 2.1.2.1
Rewrite (x+h)2(x+h)2 as (x+h)(x+h)(x+h)(x+h).
f(x+h)=(x+h)(x+h)f(x+h)=(x+h)(x+h)
Step 2.1.2.2
Expand (x+h)(x+h)(x+h)(x+h) using the FOIL Method.
Step 2.1.2.2.1
Apply the distributive property.
f(x+h)=x(x+h)+h(x+h)f(x+h)=x(x+h)+h(x+h)
Step 2.1.2.2.2
Apply the distributive property.
f(x+h)=x⋅x+xh+h(x+h)f(x+h)=x⋅x+xh+h(x+h)
Step 2.1.2.2.3
Apply the distributive property.
f(x+h)=x⋅x+xh+hx+h⋅hf(x+h)=x⋅x+xh+hx+h⋅h
f(x+h)=x⋅x+xh+hx+h⋅hf(x+h)=x⋅x+xh+hx+h⋅h
Step 2.1.2.3
Simplify and combine like terms.
Step 2.1.2.3.1
Simplify each term.
Step 2.1.2.3.1.1
Multiply xx by xx.
f(x+h)=x2+xh+hx+h⋅hf(x+h)=x2+xh+hx+h⋅h
Step 2.1.2.3.1.2
Multiply hh by hh.
f(x+h)=x2+xh+hx+h2f(x+h)=x2+xh+hx+h2
f(x+h)=x2+xh+hx+h2f(x+h)=x2+xh+hx+h2
Step 2.1.2.3.2
Add xhxh and hxhx.
Step 2.1.2.3.2.1
Reorder xx and hh.
f(x+h)=x2+hx+hx+h2f(x+h)=x2+hx+hx+h2
Step 2.1.2.3.2.2
Add hxhx and hxhx.
f(x+h)=x2+2hx+h2f(x+h)=x2+2hx+h2
f(x+h)=x2+2hx+h2f(x+h)=x2+2hx+h2
f(x+h)=x2+2hx+h2f(x+h)=x2+2hx+h2
Step 2.1.2.4
The final answer is x2+2hx+h2x2+2hx+h2.
x2+2hx+h2x2+2hx+h2
x2+2hx+h2x2+2hx+h2
x2+2hx+h2x2+2hx+h2
Step 2.2
Reorder.
Step 2.2.1
Move x2x2.
2hx+h2+x22hx+h2+x2
Step 2.2.2
Reorder 2hx2hx and h2h2.
h2+2hx+x2h2+2hx+x2
h2+2hx+x2h2+2hx+x2
Step 2.3
Find the components of the definition.
f(x+h)=h2+2hx+x2f(x+h)=h2+2hx+x2
f(x)=x2f(x)=x2
f(x+h)=h2+2hx+x2f(x+h)=h2+2hx+x2
f(x)=x2f(x)=x2
Step 3
Plug in the components.
f(x+h)-f(x)h=h2+2hx+x2-(x2)hf(x+h)−f(x)h=h2+2hx+x2−(x2)h
Step 4
Step 4.1
Simplify the numerator.
Step 4.1.1
Subtract x2x2 from x2x2.
h2+2hx+0hh2+2hx+0h
Step 4.1.2
Add h2+2hxh2+2hx and 00.
h2+2hxhh2+2hxh
Step 4.1.3
Factor hh out of h2+2hxh2+2hx.
Step 4.1.3.1
Factor hh out of h2h2.
h⋅h+2hxhh⋅h+2hxh
Step 4.1.3.2
Factor hh out of 2hx2hx.
h(h)+h(2x)hh(h)+h(2x)h
Step 4.1.3.3
Factor hh out of h(h)+h(2x)h(h)+h(2x).
h(h+2x)hh(h+2x)h
h(h+2x)hh(h+2x)h
h(h+2x)hh(h+2x)h
Step 4.2
Reduce the expression by cancelling the common factors.
Step 4.2.1
Cancel the common factor of hh.
Step 4.2.1.1
Cancel the common factor.
h(h+2x)h
Step 4.2.1.2
Divide h+2x by 1.
h+2x
h+2x
Step 4.2.2
Reorder h and 2x.
2x+h
2x+h
2x+h
Step 5
Replace the variable x with 0 in the expression.
2(0)+h
Step 6
Multiply 2 by 0.
0+h
Step 7
Add 0 and h.
h
Step 8