Variation Objectives: Construct a Model using Direct Variation Construct a Model using Inverse Variation Construct a Model using Joint or Combined Variation
Variation: how one quantity varies in relation to another quantity Direct Variation: y varies directly with x or y is directly proportional to x if there exists a constant k such that Inverse Variation: y varies inversely as x or y is inversely proportional to x if there exists a constant k such that Variation: how one quantity varies in relation to another quantity
Write a General Formula to describe each Variation If a varies directly with b and a = 5 when b = 20. Find a when b = 136. If r is inversely proportional to the square root of y and r = 3/2 when y = 16. Find r when y = 6561
Joint Variation: z varies jointly as x and y or z is jointly proportional to x and y if there exists a constant k such that Combined Variation: combinations of direct and/or inverse and/or joint variation that occur at the same time Solving Variation Problems 1. Write an equation that describes the given English statement. 2. Substitute the given pair of values into the equation in step 1 and solve for k, the constant of variation. 3. Substitute the value of k into the equation in step 1. 4. Use the equation from step 3 to answer the problem’s question.
Write a General Formula to describe each Variation If w varies jointly with m and the cube of z and w = 128 when m = 6 and z = 2. Find w when m = 4 and z = 3 If t is jointly proportional to the square root of a and b squared and inversely proportional to c and t = 2 when a = 9, b = 5 and c = 150. Find t when a = 16, b = 3 and c = 24.
5. The distance that an object falls is directly proportional to the square of the time of the fall. If an object falls 64 feet in 2 seconds, how far will if fall in 5 seconds? How long will it take the object to fall 784 feet?