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1. Which of the following represents a function?

x -2 -1 0 -1 -2
y 2 3 4 5 6

x 1 1 0 2 2
y 1 2 3 4 5

x 1 2 3 4 5
y 2 2 3 3 4

x 1 1 1 1 1
y 2 3 4 5 6

2. What is the domain of the function: {(2, 1); (4, 2); (6, 3); (8, 4)}?
{1, 2, 3, 4}
{1, 2, 3, 4, 6, 8}
{2, 4, 6, 8}
{6, 8}

3. What is the range of the function: {(2, 1); (4, 2); (6, 3); (8, 4)}?
{1, 2, 3, 4}
{1, 2, 3, 4, 6, 8}
{2, 4, 6, 8}
{6, 8}

4. Suppose p varies directly with d, and p = 7 when d = 3. What is the value of d when p = 28?
4/3
12
16
140/3

5. Given the function T(z) = 7 − z, find T(−4).
−11
11
−3
3
6. What is the equation of the graph?

f(x) = − |x| + 2
f(x) = − |x| − 2
f(x) = − |x + 2|
f(x) = − |x − 2|
7. The number of calories burned, C, varies directly with the time spent exercising, t. When Dennis walks for 4 hours, he burns 800 calories. Which of the following equations shows this direct linear variation?
C = t
C = 800t
C = 4t
C = 200t

1. Which of the following represents a function? x -2 -1 0 -1 -2 y 2 3 4 5 6 x 1 1 0 2 2 y-example-1
User Dedman
by
8.6k points

2 Answers

3 votes
1. 3rd one, because for each x there's only one y.

2. The domain are x's, so it's {2, 4, 6, 8}

3. The range are y's, so it's {1, 2, 3, 4}

4.

p=kd\\ 7=3k\\ k=(7)/(3)\\ p=(7)/(3)d\\ d=(3)/(7)p\\ d=(3)/(7)\cdot28=12

5.

T(-4)=7-(-4)=7+4=11

6.
f(x) = - |x| + 2

7.

C=kt\\ 800=4k\\ k=200\\ C=200t


User Geotheory
by
8.1k points
7 votes

1.\\\#1\ not\ because\ for\ x=-2\to y=2\ and\ y=6\\\#2\ not\ because\ for\ x=1\to y=1\ and\ y=2\\\#3\ \boxed{IT'S\ OK}\leftarrow answer\\\#4\ not\ because\ for\ x=1\to y=2\ and\ y=3\ and...


2.\ (x;\ y)\to x\in D-domain\\\\therefore:\\\\\{(2;1);\ (4;2);\ (6;\ 3);\ (8;\ 4)\}\\\\\boxed{The\ domain\ D=\{2;\ 4;\ 6;\ 8\}}


3.\ (x;\ y)\to y\in Range\\\\\{(2;\ 1);\ (4;\ 2);\ (6;\ 3);\ (8;\ 4)\}\\\\\boxed{the\ range:\{1;\ 2;\ 3;\ 4\}}


4.\\(p)/(d)=constans\\\\(28)/(d)=(7)/(3)\ \ \ \ |cross\ multiply\\\\7\cdot d=3\cdot28\ \ \ \ |divide\ both\ sides\ by\ 7\\\\d=(84)/(7)\\\\\boxed{d=12}


5.\ T(z)=7-z\\\\T(-4)\to z=-4\\\\put\ the\ value\ of\ z\ to\ (7-z):\\\\T(-4)=7-(-4)=7+4=\boxed{11}


6.\\y=|x|\to\ the\ axis\ of\ symmetry\ is\ OY\ (S_(OY))\\\\y=-|x|\to\ the\ axis\ of\ symmetry\ is\ OX\ (S_(OX))\\\\so....\ the\ y-intercept\ is\ (0;\ 2),\ therefore\ answer\ is\ \boxedx


7.\\\begin{array}{ccc}C&-&t\\800&-&4\end{array}\ \ \ \ |cross\ multiply\\\\4C=800t\ \ \ \ \ |divide\ both\ sides\ by\ 4\\\\\boxed{C=200t}
User Soyuka
by
7.6k points