To Be a Function or Not To Be a Function
(2, 4), (3, 6), (4, 8), (2, 10)
Not a function. The input x = 2 is mapped to two different outputs
Evaluate 3x + 7 for x = 4.
19
Evaluate y = 3x - 5 for x = -2.
y = -11
Solve x - 8 = 15.
x = 23
Evaluate 12 - 3 + 4.
13
x: -2, -1, 0, 1, 2
y: 4, 1, 0, 1, 4
Function. Every input (x-value) is mapped to exactly one output (y-value). It is perfectly fine for different inputs to share the same output.
Evaluate 2a - 5 for a = -3.
-11
Evaluate y = -2x + 8 for x = -1.
y = 10
Solve -4x = 28.
x = -7
Evaluate 5 + (8 - 2) /3.
7
Does the graph of a perfect circle represent a function?
POWER: GET THIS RIGHT AND TAKE AWAY UP TO 200 POINTS FROM ANOTHER TEAM.
Not a function. A circle fails the vertical line test because a vertical line will intersect the graph at two distinct points.
Evaluate -4m + 12 for m = 6.
-12
Evaluate y = x - 4x + 3 for x = 0.
DAILY DOUBLE: CHOOSE YOUR TEAM TO GET POINTS OR TAKE AWAY POINTS FROM ANOTHER TEAM. CAN WAGER UP TO 500 POINTS! IF THE TEAM I CALL ON GETS THE QUESTION WRONG IT DOES THE OPPOSITE OF WHAT YOU WANTED!
y = 3.
Solve 3x + 5 = 20.
x = 5
Evaluate 4^2 - 10/2.
11
In a mapping diagram, the input x = 5 has a single arrow pointing to y = 10, and the input x = 7 has a single arrow pointing to y = 10. Is this relation a function?
Function. Each individual input (5 and 7) points to exactly one output.
Evaluate 20/k + 8 for k = 5.
12
Evaluate y = 5 - 4x for x = 1.
y = 1.
Solve x/3 - 4 = 2.
x = 18
Evaluate 3 x (4 + 1) - 6.
9
Is the equation y=x^2 a function? Try putting values in for x, and making a table.
Function. No problems here.
Evaluate y - 4y + 5 for y = 2.
-1
Evaluate y = -x + 6 for x = 2.
y = 4.
Solve -5y + 12 = -3.
y = 3
Evaluate 20/4 x 2 + 3^2.
POWER: GET THIS RIGHT AND TAKE AWAY 300 POINTS FROM ANOTHER TEAM.
19