WeBWorK : mathprep : Section09SettingUpFunctionsTest : v9

Problem 1.

(1 point)

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

Problem 2.

(1 point)

An interval is specified by $a < x < b$ . Which of the following is true?

A. $a$ and $b$ represent variables, and $x$ is a constant.
B. $x$ represents a variable, and $a, b$ are constants.
C. All of $a$ , $b$ and $x$ represent variables.
D. $x$ is the name of a function and $a, b$ represent constants.
E. $x$ is the name of a function and $a, b$ represent variables.

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Problem 3.

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

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Problem 4.

(1 point)

The amount of material, $A$ , that a student remembers $t$ hours after memorizing it is given as a function of time by $A(t) = (A_0 - A_1) + A_1 ({1\over2})^{t/h}$ , where $A_0$ is the initial amount of material memorized, $A_1$ the amount the student will remember, and $h$ the half-life of material that is forgotten. Which of the following is true?

A. $A$ is the name of a function, $h$ is a variable, and $t$ , $A_0$ and $A_1$ are constants.
B. $A$ is the name of a function, $t$ is a variable, and $A_0$ , $A_1$ and $h$ are constants.
C. $A$ , $t$ and $h$ are variables, and $A_0$ and $A_1$ are constants.
D. $A$ and $t$ are the names of functions, and $A_0$ , $A_1$ and $h$ are constants.
E. None of the other options is true.

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Problem 5.

(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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