Direct and Inverse Variation

What is direct variation?

• Direct variation is a mathematical relationship between two variables where one variable decreases as the other variable decreases.

• Direct variation is a mathematical relationship between two variables where one variable increases as the other variable increases, following the form y = kx, where k is a constant of proportionality.

• Direct variation is a mathematical relationship between two variables where one variable decreases as the other variable increases.

• Direct variation is a mathematical relationship between two variables where one variable remains constant as the other variable increases.

What is inverse variation?

• Inverse variation is a relationship between two variables in which one variable increases as the other increases.

• Inverse variation is a relationship between two variables in which one variable increases as the other decreases, and vice versa.

• Inverse variation is a relationship between two variables in which one variable decreases as the other decreases.

• Inverse variation is a relationship between two variables in which one variable remains constant as the other changes.

If y varies directly as x, and y = 15 when x = 3, find y when x = 6.

• 25

• 12

• 18

• 30

If y varies inversely as x, and y = 10 when x = 5, find y when x = 2.

• 15

• 20

• 30

• 25

State the equation for direct variation.

State the equation for inverse variation.

If the speed of a car varies directly as the distance it travels, and the car is traveling at 60 km/h when it has traveled 150 km, what is the speed of the car when it has traveled 300 km?

• 120 km/h

• 80 km/h

• 90 km/h

• 100 km/h

If the temperature varies inversely as the number of layers of clothing, and the temperature is 20°C when wearing 2 layers, find the temperature when wearing 5 layers.

• 10°C

• 40°C

• 8°C

• 5°C

y is inversely proportional to the cube root of x.

Which statement is correct?

The height (h) of a plant varies directly as the square of the amount of sunlight (s).

Which statement is correct?