3.2 Flashcards
What is a directly proportional relationship?
A relationship where two variables change in the same ratio when one becomes k times as large, the other also becomes k times as large.
What is the formula for a directly proportional relationship?
y = kx
What does the variable k represent in the formula y = kx?
The constant of proportionality
If y = 3x, what is the constant of proportionality?
3
What happens to y when x becomes four times as large in the relationship y = 3x?
y becomes four times as large
Fill in the blank: A directly proportional relationship has a y-intercept of _______.
0
True or False: The graph of a directly proportional relationship is a line that passes through the origin.
True
What is the gradient of the line in a directly proportional relationship?
It is equal to the constant of proportionality.
In the ratio table for y = 3x, what is the ratio of y to x?
3
What does a table of values corresponding to a directly proportional relationship show?
The ratio of the two numbers is equal for each column.
If x = 1 in the equation y = 3x, what is the value of y?
3
If x = 10 in the equation y = 3x, what is the value of y?
30
If x = 100 in the equation y = 3x, what is the value of y?
300