Drone Velocity Limit Temperature
1. **Problem 1: Find the instantaneous velocity and acceleration of the drone at $t=5$ given $s(t) = 7t^3 - 3t^2 - 5t + 2$.**
2. The instantaneous velocity is the first derivative of position with respect to time:
$$v(t) = s'(t) = \frac{d}{dt}(7t^3 - 3t^2 - 5t + 2) = 21t^2 - 6t - 5$$
3. Evaluate velocity at $t=5$:
$$v(5) = 21(5)^2 - 6(5) - 5 = 21 \times 25 - 30 - 5 = 525 - 35 = 490$$
4. The acceleration is the derivative of velocity with respect to time:
$$a(t) = v'(t) = \frac{d}{dt}(21t^2 - 6t - 5) = 42t - 6$$
5. Evaluate acceleration at $t=5$:
$$a(5) = 42(5) - 6 = 210 - 6 = 204$$
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6. **Problem 2: Evaluate $\lim_{(x,y) \to (0,0)} f(x,y)$ for $f(x,y) = \frac{x^2 y}{2 + y^2}$.**
7. Substitute $(0,0)$ directly:
$$f(0,0) = \frac{0^2 \times 0}{2 + 0^2} = 0$$
8. Check limit along $y=0$:
$$f(x,0) = \frac{x^2 \times 0}{2 + 0} = 0$$
9. Check limit along $x=0$:
$$f(0,y) = \frac{0 \times y}{2 + y^2} = 0$$
10. Since the function approaches 0 along different paths, the limit is:
$$\lim_{(x,y) \to (0,0)} f(x,y) = 0$$
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11. **Problem 3: Compute $\frac{\partial T}{\partial x}$ and $\frac{\partial T}{\partial y}$ at $(1,2)$ for $T(x,y) = 4x^2 y - y^3 + 2$.**
12. Partial derivative with respect to $x$:
$$\frac{\partial T}{\partial x} = \frac{\partial}{\partial x}(4x^2 y - y^3 + 2) = 8xy$$
13. Evaluate at $(1,2)$:
$$\frac{\partial T}{\partial x}(1,2) = 8 \times 1 \times 2 = 16$$
14. Partial derivative with respect to $y$:
$$\frac{\partial T}{\partial y} = \frac{\partial}{\partial y}(4x^2 y - y^3 + 2) = 4x^2 - 3y^2$$
15. Evaluate at $(1,2)$:
$$\frac{\partial T}{\partial y}(1,2) = 4 \times 1^2 - 3 \times 2^2 = 4 - 12 = -8$$