WeBWorK : mathprep : Section09SettingUpFunctionsTest : v8

Problem 1.

(1 point)

If $f = a^{-x}$ , what is the coefficient of $x$ ?

Problem 2.

(1 point)

The function giving the amount of medicine remaining in the bloodstream $t$ hours after it has been administered is $M(t) = M_0 e^{-8.3t/h}$ , where $h$ is the medicine's half-life and $M_0$ is the initial dose. Which of the following is true?

A. $M$ and $M_0$ are names of functions, $t$ represents a variable, and $h$ is constant.
B. $M$ is the name of a function, $h$ represents a variable, and $M_0$ and $t$ are constants.
C. $M$ , $t$ and $h$ represent variables, and $M_0$ is a constant.
D. $M$ is the name of a function, $t$ represents a variable, and $M_0$ and $h$ are constants.
E. All of $M$ , $M_0$ , $t$ and $h$ represent variables.

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Problem 3.

(1 point)

In the height function $H(t) = AB^t$ , which of the following is true?

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

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Problem 4.

(1 point)

If $s=-16t^2-2t+1$ , what is the coefficient of $t^2$ ?

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Problem 5.

(1 point)

If $A=\pi r^2$ and $r = 3t^2$ , write a formula for $A$ as a function of $t$ .
$A(t) =$

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Problem 6.

(1 point)

Write a formula for the function $V(r)$ if $V={1\over3}\pi r^2h$ and ${r\over6}={h\over10}$ .
$V(r) =$

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Problem 7.

(1 point)

The bank balance resulting from an initial deposit of $P_0$ dollars is given as a function of time $t$ (in years) by $B(t) = P_0(1 + {r\over12})^{12 t}$ , where $r$ is a fixed annual interest rate compounded monthly. Which of the following is true?

A. $B$ , $t$ and $r$ represent variables, and $P_0$ is constant.
B. $B$ is the name of a function, $t$ represents a variable, and $P_0, r$ are constants.
C. $B$ is the name of a function, $r$ and $t$ represent variables, and $P_0$ is constant.
D. $B$ and $P_0$ are names of functions, $t$ represents a variable, and $r$ is constant.
E. All of $B$ , $t$ and $P_0$ are variables, and $r$ is constant.

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