Find the difference quotient and simplify your answer.

[tex]\[ f(x) = x^2 - 2x + 1 \][/tex]

[tex]\[ \frac{f(4+h) - f(4)}{h}, \quad h \neq 0 \][/tex]



Answer :

To find the difference quotient for the given function [tex]\( f(x) = x^2 - 2x + 1 \)[/tex], we need to follow these steps:

1. Compute [tex]\( f(4+h) \)[/tex].
2. Compute [tex]\( f(4) \)[/tex].
3. Formulate the difference quotient [tex]\(\frac{f(4+h) - f(4)}{h}\)[/tex].

Let's start with the calculations.

### Step 1: Compute [tex]\( f(4+h) \)[/tex]
Substitute [tex]\( 4+h \)[/tex] into the function [tex]\( f(x) \)[/tex]:
[tex]\[ f(4+h) = (4+h)^2 - 2(4+h) + 1 \][/tex]

Expand and simplify the expression:
[tex]\[ (4+h)^2 = 16 + 8h + h^2 \][/tex]
[tex]\[ - 2(4+h) = -8 - 2h \][/tex]
So,
[tex]\[ f(4+h) = 16 + 8h + h^2 - 8 - 2h + 1 \][/tex]
Simplify further:
[tex]\[ f(4+h) = h^2 + 6h + 9 \][/tex]

### Step 2: Compute [tex]\( f(4) \)[/tex]
Substitute [tex]\( 4 \)[/tex] into the function [tex]\( f(x) \)[/tex]:
[tex]\[ f(4) = (4)^2 - 2(4) + 1 \][/tex]
[tex]\[ f(4) = 16 - 8 + 1 \][/tex]
[tex]\[ f(4) = 9 \][/tex]

### Step 3: Formulate the difference quotient
Now, construct the difference quotient:
[tex]\[ \frac{f(4+h) - f(4)}{h} \][/tex]

Substitute the values calculated in Steps 1 and 2:
[tex]\[ \frac{h^2 + 6h + 9 - 9}{h} \][/tex]
Simplify the numerator:
[tex]\[ \frac{h^2 + 6h}{h} \][/tex]

Since [tex]\( h \neq 0 \)[/tex], we can factor out [tex]\( h \)[/tex] from the numerator:
[tex]\[ \frac{h(h + 6)}{h} \][/tex]
Cancel out [tex]\( h \)[/tex] in the numerator and the denominator:
[tex]\[ h + 6 \][/tex]

Therefore, the simplified difference quotient is:
[tex]\[ \boxed{h + 6} \][/tex]

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