Direct, Joint, and Inverse Variation Flashcard

Front

What is direct variation?

Back

Direct variation is a relationship between two variables where one variable is a constant multiple of the other. It can be expressed as y = kx, where k is a non-zero constant.

Front

What is inverse variation?

Back

Inverse variation is a relationship between two variables where the product of the two variables is a constant. It can be expressed as xy = k, where k is a non-zero constant.

Front

What is joint variation?

Back

Joint variation is a relationship where a variable varies directly with the product of two or more other variables. It can be expressed as y = kxz, where k is a non-zero constant.

Front

If y varies directly as x and y = 10 when x = 2, what is y when x = 5?

Back

y = 25.

Front

If y varies inversely with x and y = 20 when x = 4, what is y when x = 10?

Back

y = 8.

Front

If y varies jointly as x and z, and y = 30 when x = 3 and z = 2, what is y when x = 6 and z = 4?

Back

y = 120.

Front

What does the equation w = 10chs represent?

Back

The equation represents joint variation.

Front

If y = 150 when x = 2 in an inverse variation, what is y when x = 25?

Back

y = 12.

Front

What does the equation xy = 25 represent?

Back

The equation represents inverse variation.

Front

If y varies directly as x and y = 22.5 when x = 15, what is y when x = 20?

Back

y = 30.