1. **Plot the graphs of the functions:**
a) The function is $y=3x^2-7$.
- This is a quadratic function with a parabola opening upwards.
b) The function is $y=x^3-4x^2+4x$.
- This is a cubic function with possible turning points.
2. **Calculate the inverse of the functions:**
a) Given $f(x)=\frac{4x+2}{5}$.
- To find the inverse, set $y=\frac{4x+2}{5}$.
- Multiply both sides by 5: $5y=4x+2$.
- Solve for $x$: $4x=5y-2$.
- $x=\frac{5y-2}{4}$.
- Swap $x$ and $y$ to get the inverse function:
$$f^{-1}(x)=\frac{5x-2}{4}$$
b) Given $f(x)=(x+3)^3-5$.
- Set $y=(x+3)^3-5$.
- Add 5 to both sides: $y+5=(x+3)^3$.
- Take cube root: $\sqrt[3]{y+5}=x+3$.
- Solve for $x$: $x=\sqrt[3]{y+5}-3$.
- Swap $x$ and $y$:
$$f^{-1}(x)=\sqrt[3]{x+5}-3$$
3. **Evaluate the limits:**
a) $\lim_{x\to -5} \frac{x^2-25}{x^2+2x-15}$
- Factor numerator: $x^2-25=(x-5)(x+5)$.
- Factor denominator: $x^2+2x-15=(x+5)(x-3)$.
- Simplify: $\frac{(x-5)(x+5)}{(x+5)(x-3)}=\frac{x-5}{x-3}$ for $x\neq -5$.
- Substitute $x=-5$: $\frac{-5-5}{-5-3}=\frac{-10}{-8}=\frac{5}{4}$.
b) $\lim_{x\to 0} \frac{(6+x)^2-36}{x}$
- Expand numerator: $(6+x)^2=36+12x+x^2$.
- Numerator becomes $36+12x+x^2-36=12x+x^2$.
- Expression: $\frac{12x+x^2}{x}=12+x$ for $x\neq 0$.
- Substitute $x=0$: $12+0=12$.
c) $\lim_{x\to 5} (10 + |x-5|)$
- As $x\to 5$, $|x-5|\to 0$.
- Limit is $10+0=10$.
d) $\lim_{x\to 1} f(x)$ where
$$f(x)=\begin{cases} 7-4x, & x<1 \\ x^2+2, & x\geq 1 \end{cases}$$
- Left-hand limit: $\lim_{x\to 1^-} 7-4x=7-4(1)=3$.
- Right-hand limit: $\lim_{x\to 1^+} x^2+2=1+2=3$.
- Since both limits equal 3, the limit exists and is 3.
**Final answers:**
- Inverse functions:
$$f^{-1}(x)=\frac{5x-2}{4}$$ and $$f^{-1}(x)=\sqrt[3]{x+5}-3$$
- Limits:
$$\lim_{x\to -5} \frac{x^2-25}{x^2+2x-15}=\frac{5}{4}$$
$$\lim_{x\to 0} \frac{(6+x)^2-36}{x}=12$$
$$\lim_{x\to 5} (10 + |x-5|)=10$$
$$\lim_{x\to 1} f(x)=3$$
Functions Inverses Limits
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