1. **Problem:** Find the first and second derivatives of $f(x) = x^2 + x + 8$.
Formula: For $f(x) = x^n$, $f'(x) = nx^{n-1}$ and $f''(x) = n(n-1)x^{n-2}$.
Step 1: First derivative:
$$f'(x) = 2x + 1 + 0 = 2x + 1$$
Step 2: Second derivative:
$$f''(x) = 2 + 0 = 2$$
2. **Problem:** Find the first and second derivatives of $f(x) = 5x^3 - 3x^5$.
Step 1: First derivative:
$$f'(x) = 15x^2 - 15x^4$$
Step 2: Second derivative:
$$f''(x) = 30x - 60x^3$$
3. **Problem:** Find the first and second derivatives of $f(x) = \frac{x^3 + 7}{x}$.
Rewrite:
$$f(x) = x^2 + \frac{7}{x} = x^2 + 7x^{-1}$$
Step 1: First derivative:
$$f'(x) = 2x - 7x^{-2} = 2x - \frac{7}{x^2}$$
Step 2: Second derivative:
$$f''(x) = 2 + 14x^{-3} = 2 + \frac{14}{x^3}$$
4. **Problem:** Find the first and second derivatives of $f(x) = (x+1)(x-1)$.
Step 1: Expand:
$$f(x) = x^2 - 1$$
Step 2: First derivative:
$$f'(x) = 2x$$
Step 3: Second derivative:
$$f''(x) = 2$$
5. **Problem:** Find the first and second derivatives of $f(t) = \frac{t^2 + 5t - 1}{t^2}$.
Rewrite:
$$f(t) = 1 + 5t t^{-2} - t^{-2} = 1 + 5t^{-1} - t^{-2}$$
Step 1: First derivative:
$$f'(t) = 0 - 5t^{-2} + 2t^{-3} = -\frac{5}{t^2} + \frac{2}{t^3}$$
Step 2: Second derivative:
$$f''(t) = 10t^{-3} - 6t^{-4} = \frac{10}{t^3} - \frac{6}{t^4}$$
6. **Problem:** Find the first and second derivatives of $f(x) = \frac{1}{2}x^2 + 3x - 4$.
Step 1: First derivative:
$$f'(x) = x + 3$$
Step 2: Second derivative:
$$f''(x) = 1$$
7. **Problem:** Find the first and second derivatives of $f(x) = \frac{x^3}{3} + \frac{x^2}{2} + \frac{x}{4}$.
Step 1: First derivative:
$$f'(x) = x^2 + x + \frac{1}{4}$$
Step 2: Second derivative:
$$f''(x) = 2x + 1$$
Derivatives Exercise 1D658F
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