Bell Ringer

Learning Target: I can solve an equation for the constant of variation.

Direct Variation

A DIRECT VARIATION IS A FUNCTION IN THE FORM

Y = KX WHERE K DOES NOT EQUAL 0.

DEFINITION: DIRECT VARIATION

THE CONSTANT OF VARIATION IS K, THE COEFFICIENT OF X.

DEFINITION: CONSTANT OF VARIATION

Write and Solve a Direct Variation Equation

A. Suppose y varies directly as x, and y = 9 when x = –3. Write a direct variation equation that relates x and y.

B. Use the direct variation equation to find x when y = 15.

Write and Solve a Direct Variation Equation

A. –3

B. 9

C. –15

D. –5

B. Suppose y varies directly as x, and y = 15 when x = 5. Use the direct variation equation to find x wheny = –45.

Write and Solve a Direct Variation Equation

B. Dustin ran a 26-mile marathon in 3.25 hours. Graph the equation.

A. B.

C. D.

Write and Solve a Direct Variation Equation

C. Estimate how many hours it would take to jog 16 miles.

A. 1 hour

B.

C. 16 hours

D. 2 hours

Write and Solve a Direct Variation Equation

Suppose y varies directly as x, and y = 24 and x = 4. Find y when x = 16.

Write and Solve a Direct Variation Equation

Suppose y varies directly as x, and y = 36 and x = 2. Find y when x = 6.

Write and Solve a Direct Variation Equation

Homework

DV Worksheet