WeBWorK : mathprep : Section09SettingUpFunctionsTest : v10

Problem 1.

(1 point)

You are told that the difference between two functions is constant, $f(x) - g(x) = C$ . Which of the following is true?

A. $f$ and $g$ are names of functions, and $x$ and $C$ both represent variables.
B. All of $f, g, x$ are names of functions and $C$ is a constant.
C. $f$ and $g$ are names of functions, $x$ represents a variable, and $C$ is a constant.
D. All of $f, g, x$ are names of functions and $C$ is a variable.
E. $x$ is the name of a function, $f, g$ are variables, and $C$ is a constant.

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Problem 2.

(1 point)

A right circular cone with height $h$ and radius $r$ has volume $V = {1\over 3}\pi r^2 h$ . Write a formula for $V(r)$ if its height is four times as long as its radius.
$V(r) =$

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Problem 3.

(1 point)

If $P=P_0 e^{kt}$ , what is the coefficient of $t$ ?

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Problem 4.

(1 point)

Write a formula for $x$ as a function of $y$ if $y = {6\over 1+x}$ .
$x(y) =$

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Problem 5.

(1 point)

A function representing voltage fluctuates according to $V(t) = V_0 \cos(120\pi t)$ , where $V_0$ is the initial voltage. Which of the following is true?

A. $V$ is the name of a function, $V_0$ represents a variable, and $t$ and $\pi$ are constants.
B. $V$ is the name of a function, $t$ represents a variable, and $V_0$ and $\pi$ are constants.
C. $V_0$ is the name of a function, $V$ and $t$ are variables, and $\pi$ is a constant.
D. $V$ , $V_0$ and $t$ are variables and $\pi$ is a constant.
E. $V$ is the name of a function, $V_0$ and $t$ represent variables, and $\pi$ is constant.

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Problem 6.

(1 point)

If $f = \sin(2\pi\theta + {\pi\over2})$ , what is the coefficient of $\theta$ ?

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Problem 7.

(1 point)

$P$ dollars are deposited in a bank account with a fixed annual interest rate, $r$ , compounded continuously. After $t$ years, the balance in the account is $B = P e^{rt}$ . Which of the following is true?

A. $B$ and $t$ represent variables, and $P, r$ are constants
B. $B$ , $t$ and $r$ represent variables, and $P$ is constant.
C. $P$ is the name of a function, $B$ and $t$ represent variables, and $r$ is constant.
D. $B$ and $t$ are names of functions, $t$ represents a variable, and $P$ and $r$ are constants.
E. $B$ and $P$ are names of functions, $t$ represents a variable, and $r$ is constant.

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