C.A. Notes 8-1 All equations must be solved for y y =ax Direct variation Inverse variation y =a/x Joint variation
y =axz
The word "varies" translates into an equal sign in math x varies directly with y y varies directly with x g varies directly with b
the constant a must be solved for, you will plug numbers in for x and y To write a variation equation, you must leave x and y as variables and plug in a number for a
Examples Variables x and y vary inversely, and y=7 when x=4. Write an equation
Y varies directly with x. Y=3 when x=4. Write the equation
Joint variation z varies jointly with x and y. Z=18 when x=2 and y=6. Write the equation that models this relationship