Difference Quotient 4Dfdb8
1. **State the problem:** We are given the function $f(x) = 2x^2 - 5x + 1$ and need to evaluate the difference quotient $$\frac{f(a+h) - f(a)}{h}$$ where $h \neq 0$.
2. **Recall the formula:** The difference quotient represents the average rate of change of the function over the interval from $a$ to $a+h$. It is given by $$\frac{f(a+h) - f(a)}{h}$$.
3. **Calculate $f(a+h)$:** Substitute $x = a+h$ into $f(x)$:
$$f(a+h) = 2(a+h)^2 - 5(a+h) + 1$$
Expand the square:
$$= 2(a^2 + 2ah + h^2) - 5a - 5h + 1$$
Distribute:
$$= 2a^2 + 4ah + 2h^2 - 5a - 5h + 1$$
4. **Calculate $f(a)$:** Substitute $x = a$:
$$f(a) = 2a^2 - 5a + 1$$
5. **Form the numerator $f(a+h) - f(a)$:**
$$= (2a^2 + 4ah + 2h^2 - 5a - 5h + 1) - (2a^2 - 5a + 1)$$
Simplify by subtracting:
$$= 2a^2 + 4ah + 2h^2 - 5a - 5h + 1 - 2a^2 + 5a - 1$$
Combine like terms:
$$= 4ah + 2h^2 - 5h$$
6. **Divide by $h$:**
$$\frac{4ah + 2h^2 - 5h}{h}$$
Factor $h$ from numerator:
$$= \frac{h(4a + 2h - 5)}{h}$$
Cancel $h$ (since $h \neq 0$):
$$= 4a + 2h - 5$$
7. **Final answer:**
$$\boxed{4a + 2h - 5}$$
This expression gives the average rate of change of $f(x)$ from $x=a$ to $x=a+h$.