Direct variation

Front

What is a direct variation?

Back

A proportional linear relationship.

Front

If y varies directly as x, when y = 10 and x = 2, what is y when x = 3?

Back

15

Front

A direct variation represents a proportional relationship. Which table represents a direct variation?

Back

(Example Table: x: 1, 2, 3; y: 2, 4, 6) - y is proportional to x.

Front

Which tables show a direct variation?

Back

(Example Tables: Table 1: x: 1, 2, 3; y: 2, 4, 6; Table 2: x: 1, 3, 5; y: 3, 9, 15 - only Table 1 shows direct variation.)

Front

A direct variation uses a scale factor. Which applies a scale factor of 5?

Back

y = 5x

Front

What is the general form of a direct variation equation?

Back

y = kx, where k is the constant of variation.

Front

If k = 3 in the equation y = kx, what is y when x = 4?

Back

y = 12.

Front

How do you determine if a set of points represents a direct variation?

Back

Check if the ratio of y to x is constant.

Front

What is the constant of variation in the equation y = 2x?

Back

The constant of variation is 2.

Front

If y = 8 when x = 4, what is the constant of variation?

Back

k = 2.