Derivative Linear
1. We need to find the derivative $f'(x)$ of the function $f(x) = 4x + 7$ using the definition of the derivative.
2. The definition of the derivative at a point $x$ is given by:
$$f'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}$$
3. Substitute $f(x) = 4x + 7$ into the formula:
$$f'(x) = \lim_{h \to 0} \frac{4(x+h) + 7 - (4x + 7)}{h}$$
4. Simplify the numerator:
$$4(x+h) + 7 - 4x - 7 = 4x + 4h + 7 - 4x -7 = 4h$$
5. So the expression becomes:
$$f'(x) = \lim_{h \to 0} \frac{4h}{h}$$
6. Simplify the fraction:
$$\frac{4h}{h} = 4$$ (for $h \neq 0$)
7. Take the limit as $h$ approaches 0:
$$f'(x) = \lim_{h \to 0} 4 = 4$$
8. Therefore, the derivative of $f(x) = 4x + 7$ is:
$$f'(x) = 4$$
This result means that at any point $x$, the slope of the function $4x + 7$ is 4, which aligns with the coefficient of $x$ in the linear function.