Homework # 5 - Math 149
The problems on this homework must be done alone. The honor code is in effect.
First name: Last name:
1. Which of the following represents a sinusoidal curve with its highest point at \(y = 3\) and its lowest point at \(y = -1\)?
a. \(f(x) = \sin(2x) + 2\)
b. \(f(x) = 2\sin(x) + 1\).
c. \(f(x) = 3\sin(x) + 1\).
d. \(f(x) = 3\sin(x) + 2\).
e. \(f(x) = \sin(3x) + 2\).
2. Make a sketch of the graph \( y= f(x) = (x + 1)^2 - 4 \), and use it to find the range of \(f\).
a. \( (-\infty, 2) \cup (2, \infty) \)
b. \(x \neq 2\)
c. \( (-\infty, -4] \)
d. \( [-4, \infty)\)
e. \( (\infty, \infty) \)
3. Find the domain for \( g(x) = \frac{1}{x^2 - 2x} \).
a. \( (-\infty, 0) \cup (2, \infty) \)
b. \( (-\infty, 0] \cup [2, \infty) \)
c. \([0, \infty) \)
d. All reals except 0 and 2.
e. \( (0, 2) \)
4. Find the domain for \( h(x) = \frac{1}{\sqrt{x^2 - 2x}} \).
5. The inverse of \(f(x) = \frac{x}{2} - 1\)
a. is \(f^{-1}(x) = 2x + 1\)
b. is \(f^{-1}(x) = 2x - 1\)
c. is \(f^{-1}(x) = 2x + 2\)
d. is \(f^{-1}(x) = 2(x - 1)\)
e. does not exist because the graph \(y = f(x)\) fails the horizontal line test.
6. The inverse of \(f(x) = x^3\)
a. is \(f^{-1}(x) = \frac{x}{3}\)
b. is \(f^{-1}(x) = \sqrt[3]{x}\)
c. is \(f^{-1}(x) = x^{-3}\)
d. is \(f^{-1}(x) = x^3\)
7. The inverse of \(f(x) = x^4\)
a. is \(f^{-1}(x) = \frac{x}{4}\)
b. is \(f^{-1}(x) = \sqrt[4]{x}\)
c. is \(f^{-1}(x) = x^{-4}\)
d. is \(f^{-1}(x) = x^4\)
8. Let \(f(x) = x^2 + x + 2\) and \(g(x) = e^x\). Then
a. \( (f\circ g)(x) = e^{2x} + e^x + 2\), \((g\circ f)(x) = e^{x^2 + x + 2}\)
b. \( (f\circ g)(x) = e^{x^2 + x + 2}\), \((g\circ f)(x) = e^{2x} + e^x + 2\)
c. \( (f\circ g)(x) = e^{x^2} + e^x + 2\), \((g\circ f)(x) = e^{x^2 + x + 2}\)
b. \( (f\circ g)(x) = e^{x^2 + x + 2}\), \((g\circ f)(x) = e^{x^2} + e^x + 2\)