Lesson 2 6 Notes Model Direct Variation The

Lesson 2. 6 Notes Model Direct Variation

The Equation of Direct Variation y = ax - y varies directly with x Constant of Variation - a is called the constant of variation. (Basically, a is slope) - a cannot be 0.

Important: For a relation to be considered a direct variation, THE RELATION: - MUST BE LINEAR - MUST PASS THROUGH THE ORIGIN (0, 0) (no intercept)

Graph the equation. y = 3 x

Graph the equation. y = -4 x

Graph the equation. y = 2 x + 1

Write and graph a direct variation equation that has the given ordered pair as a solution. (3, -9)

Write and graph a direct variation equation that has the given ordered pair as a solution. (-7, 4)

Write and graph a direct variation equation that has the given ordered pair as a solution. (5, 3)

Write and graph a direct variation equation that has the given ordered pair as a solution. (6, -2)

The variables x and y vary directly. Write an equation that relates x and y. Then find y when x = 12. x = 1, y = 2

The variables x and y vary directly. Write an equation that relates x and y. Then find y when x = 12. x = -2, y = 5

The variables x and y vary directly. Write an equation that relates x and y. Then find y when x = 12. x = 3, y = -2

The variables x and y vary directly. Write an equation that relates x and y. Then find x when y = -4. x = 1, y = 2

The variables x and y vary directly. Write an equation that relates x and y. Then find x when y = -4. x = -2, y = 5

Tell whether the equation represents direct variation. If so, give the constant of variation. �y = 2 x – 1 �y = 3 x � 2 x + y = 0 �y -1 = 2 x � 3 y = 4 x � 3 y -1 = x

Homework: Page 103 10 -18, 27 -35