Download Relations Review

Math 10C
Relations Review
Relations Review
1. For each relation:
i. state the independent and dependent variables.
ii. state whether it is continuous or discrete.
iii. state whether it is a function or not.
y
a)
x
b) Circumference of a circle: C  2r
c)
Sport
Equipment
puck
hockey
soccer
tennis
stick
ball
racquet
d) The number of students in this Math 10C class is dependent on the time since the warning
bell rang.
2. Find the x and y-intercept of the relation y  27  3 x . Write each one as an ordered pair.
Math 10C
Relations Review
3. State the domain and range of each relation:
a) Surface area of a cube, where s is the length of one side: SA  6s 2
b)

c) Kristen has a $10 iTunes gift card. Each song costs $0.99. The total cost is dependent on
the number of songs she buys.
4. Brad turns on the oven to bake cookies at 350 °F. The temperature of the oven as it warms up
is a function of the time since Brad turned the oven on: F t   50  60t , where t is the time in
minutes, and F t  is the temperature in °F.
a) What is the F-intercept of this function and what does it represent?
b) Determine the value of F 2 and explain what it means.
c) How long does it take for the oven to heat up to 350 °F?
d) State the domain and range of this function.
Math 10C
Relations Review
5. For the function g x   4 x  9 :
a) Find g 6
b) g x  21 ; find x.
6. This graph represents the height of a person above
the ground when they are riding on the Great
Wheel, a Ferris wheel in Beijing, China.
a) What is the maximum height the Great Wheel
reaches?
b) How long does it take to ride the Great Wheel
all the way around?
c) What is the y-intercept and what does it
represent in this context?
d) State the domain and range of this relation in any appropriate form.
e) Use the graph to estimate the value of f 5 . Explain what it means in this situation.
Math 10C
Relations Review
Answers
1. a) i. independent: x; dependent: y
ii. continuous
iii. not a function
b) i. independent: radius; dependent: circumference
ii. continuous
iii. function
c) i. independent: sport; dependent: equipment
ii. discrete
iii. not a function
d) i. independent: time since the warning bell rang; dependent: # of students in the class
ii. discrete
iii. function
2. x-intercept: (9, 0)
y-intercept: (0, 27)
3. a) D: s s  0, s  R ; R: SA SA  0, SA  R 
b) D: (, 5] ; R: [1, )
c) D: whole numbers from 0 to 10 inclusive; R: multiples of $0.99 from $0 to $9.90
4. a) The F-intercept is 50°F, and it represents the temperature of the oven before it was turned
on.
b) F 2  170 At 2 minutes, the temperature of the oven is 170°F.
c) 5 minutes
d) D: [0 min, 5 min]; R: [50°F, 350°F]
5. a) g 6  15
b) x  3
6. a) 208 m
b) 20 min
c) y-int = 15 m; The lowest part of the wheel is 15 m above ground.
d) D: [0 min, 20 min]; R: [15 m, 208 m]
e) f 5  111.5 (any estimate from 100-120 is fine)
At 5 minutes, a rider on the Great Wheel would be 111.5 metres above the ground.