1. **State the problem:** Find the equation of the tangent line to the function $y = 2x + 5$ at the point $(-1, 3)$.
2. **Recall the formula:** The equation of the tangent line to a function $y = f(x)$ at $x = a$ is given by:
$$y = f'(a)(x - a) + f(a)$$
where $f'(a)$ is the derivative of $f(x)$ evaluated at $x = a$.
3. **Find the derivative:** Since $y = 2x + 5$ is a linear function, its derivative is constant:
$$f'(x) = 2$$
4. **Evaluate the derivative at $x = -1$:**
$$f'(-1) = 2$$
5. **Evaluate the function at $x = -1$:**
$$f(-1) = 2(-1) + 5 = -2 + 5 = 3$$
6. **Write the equation of the tangent line:**
$$y = 2(x - (-1)) + 3 = 2(x + 1) + 3$$
7. **Simplify:**
$$y = 2x + 2 + 3 = 2x + 5$$
**Final answer:** The equation of the tangent line at $(-1, 3)$ is
$$y = 2x + 5$$
This matches the original function, which makes sense because the function is linear and its tangent line at any point is the function itself.
Tangent Line 439E9F
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