Function? Yes/No?
Is y=2x a function?
Yes
f(x)=-14(x-3)+4;
Find f(8).
f(8)= -14(8-3)+4
= -14(5)+4
= -70+4
f(8) = -66
For a list of ordered pairs: {(100,0), (100,1), (100,2), (100,3)}, what is the domain and range?
D: {100}
R: {0,1,2,3}
Jackie has just been assigned a new book to read for English class. The book is a collection of 18 short stories. Jackie must also write a 3-paragraph summary after reading each of the short stories. The function f(s) represents the total number of paragraphs Jackie must write, after having read s short stories. What is the domain of f(d)?
A) all whole #s from 0-3
B) all whole #s from 0-18
C) all real #s from 0-18
D) all real #s from 0-3
A) all whole #s from 0-3
B) all whole #s from 0-18
C) all real #s from 0-18
D) all real #s from 0-3
f(x) = x(-1+3x); Find f(-6).
f(-6) = -6(-1+3(-6))
= -6(-1-18)
= 6+108
= 114
Is x = -10 a function?
No
p(t) = t3+t+5;
Find p(-3).
p(t) = t3+t+5
= (-3)3+(-3)+5
= -27-3+5
p(t) = -25
For a list of ordered pairs: {(2, 4), (6, 8), (-2, 8), (5, 0)}, what is the domain and range?
D: {-2,2,5,6}
R: {0,4,8}
Peter borrowed money from the bank to buy a used car. The total amount owed is $7,200. Peter will make 36 monthly payments of $200 in order to pay off the loan. The function A(m) represents the amount Peter still owes, in dollars, after making m payments.
A) all whole #s from 0-36
B) all whole #s from 0-200
C) all real #s from 0-36
D) all real #s from 0-200
A) all whole #s from 0-36
B) all whole #s from 0-200
C) all real #s from 0-36
D) all real #s from 0-200
f(x) = 2x2-3x+26; Find f(5) and f(-2).
f(5) = 2(5)2-3(5)+26
= 2(25)-3(5)+26 = 50-15+26 = 61
f(-2) = 2(-2)2-3(-2)+26
= 2(4)-3(-2)+26 = 8+6+26 = 40
Is y = 5+x+x2 a function?
Yes
f(x) = 7(x+9)+11;
Find f(t).
f(t) = 7(t+9)+11
= 7t+63+11
f(t) = 7t + 74
What is the domain and range of y=4x2+9 with an open circle at the vertex?
Domain: all real numbers except x=0
Range: y>9
The total cost in dollars, c, to purchase video games online can be found using the function c = 16.95x + 4.75, where x is the number of video games purchased. If at least 4 games but no more than 7 games are purchased online, what is the range of the function for this situation?
{4,5,6,7}
f(x)=6x2+ax-8; Find x=4.
f(4) =6(4)2+a4-8
= 6(16)+4a-8
= 96+4a-8
= 88+4a
Is this list of ordered pairs a function?
{(0,3), (1,9), (-1, 2), (7,8), (0,10)}
No
f(x) = 4x3+x2+1;
Find f(y+z).
f(y+z) = 4(y+z)3+(y+z)2+1
What is the domain and range of y=|x|?
Domain: all real numbers
Range: y≥0
Joe had a summer job at Walmart that pays $7.00 an hour and he worked between 15-35 hours every week. His weekly salary can be modeled by the equation: S=7h, where S is his weekly salary and h is the number of hours he worked in a week. What's the domain and range?
Domain: 15≤h≤35
Range: 105≤S≤245
f(x) = 50x2-3x; Find f(a+b).
f(a+b) = 50(a+b)2-3(a+b)
True/False: If a relation contains a closed dot at (5, -9) and an open dot at (5,-1), this is not a function.
False, this IS a function.
f(x) = 20x+90x;
Find f(a+b).
f(a+b) = 20(a+b)+90(a+b)
= 20a+20b+90a+90b
= 110a+110b
What is the domain and the range of y=3x?
D: all real numbers
R: y>0
Hector's service club is raising money by wrapping presents in the mall. The function f(x) = 3x describes the amount of money, in dollars, the club will earn for wrapping x presents. They only have enough wrapping paper to wrap 1000 presents. Describe the domain and range using inequalities.
Domain: 0≤x≤1000
Range: 0≤y≤3000
f(x) = (2x+3y)/x; Find x = 8.
f(8) = (2(8)+3y)/8
= (16+3y)/8
= 2+3y/8