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Variation & Problem

Direct variation problems are solved by using the equation y=kx
Solve: The distance a body falls from rest varies directly as the square of the time it falls. If a ball falls 144 feet in three seconds, how far will the ball fall in seven seconds? Formula: y=kx--->d=kt^2 144=k(3)^2 144=9k 16=k d=16t^2 d=16(7)^2 d=784ft Answer: d=784ft
k stands for: constant of variation or constant of proportionality
Inverse variation problems are solved using the equation y=k/x
Solve: If y varies directly as x and z, and y = 5 when x = 3 and z = 4, then find y when x = 2 and z = 3 Formula: y=kxz 5 = k(3)(4) 5 = 12k 5/12 = k y = ( 5/12)xz y = ( 5/12)(2)(3) y = ( 5/12)(6) Answer: y = 5/2
Created by: rcontreras12