Limit Derivatives
1. **Problem:** Evaluate the limit $$\lim_{\Delta x \to 0} \frac{\Delta x}{\Delta x}$$.
Since for all $$\Delta x \neq 0$$, $$\frac{\Delta x}{\Delta x} = 1$$, the limit as $$\Delta x \to 0$$ is 1.
2. **Problem:** Evaluate the limit $$\lim_{x \to 0} (1 + x)^{\frac{1}{x}}$$.
This is a classic limit known to equal $$e$$ because $$\lim_{x \to 0} (1 + x)^{\frac{1}{x}} = e$$.
3. **Problem:** Find the derivative $$\frac{d}{dx} \cot x$$.
Using derivative rules, $$\frac{d}{dx} \cot x = -\csc^2 x$$.
4. **Problem:** What is the second derivative commonly called?
The second derivative of position with respect to time is called acceleration.
5. **Problem:** What physical quantity is acceleration proportional to?
By Newton's second law, acceleration is proportional to the total force acting on an object.
6. **Problem:** Determine if the equation $$x^2 y + y^3 = 4$$ is implicit or explicit.
Since $$y$$ cannot be written purely as a function of $$x$$ without rearrangement, it is an implicit equation.
7. **Problem:** Is Taylor series exact or approximate?
The Taylor series is generally an approximation of a function near a point.
8. **Problem:** What is a line that touches the graph of a function at two points called?
A line that intersects a curve at two points is called a secant line.
**Final Answers:**
1) a) 1
2) d) e
3) c) -cosec^2 x
4) b) acceleration
5) a) force
6) a) implicit
7) b) approximate
8) b) secant line