Lesson: Direct and Inverse Variation Mathematics • 9th Grade

In this lesson, we will learn how to recognise direct and inverse variation involving different powers and roots of x.

Lesson Plan

Students will be able to

identify whether two variables, where one or both are powers or roots, vary directly or inversely with each other by considering a relation between them,
write a relation between two variables given that powers or roots of the variables vary directly or inversely,
find the value of a variable given the value of another variable taken to a power or root that varies directly or inversely with it,
solve real-world problems involving powers and roots of two variables in direct or inverse variation.

Q1:

Given that varies directly as , write an equation for in terms of using as a non-zero constant.

Q2:

and are two variables, where varies directly with the multiplicative inverse of . If when , determine the values of when .

Q3:

Given that , where when , find the relation between and .