1. The problem asks for the second derivative of the function $$f(x) = x^7 + x^3 - 21$$ evaluated at $$x=1$$.
2. Recall the rules for derivatives:
- The derivative of $$x^n$$ is $$nx^{n-1}$$.
- The second derivative is the derivative of the first derivative.
3. First, find the first derivative:
$$f'(x) = \frac{d}{dx}(x^7) + \frac{d}{dx}(x^3) - \frac{d}{dx}(21) = 7x^6 + 3x^2 - 0 = 7x^6 + 3x^2$$
4. Next, find the second derivative:
$$f''(x) = \frac{d}{dx}(7x^6) + \frac{d}{dx}(3x^2) = 7 \cdot 6x^{5} + 3 \cdot 2x^{1} = 42x^{5} + 6x$$
5. Evaluate the second derivative at $$x=1$$:
$$f''(1) = 42(1)^5 + 6(1) = 42 + 6 = 48$$
6. Therefore, the second derivative of the function at $$x=1$$ is **48**.
Second Derivative 365E51
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.