Direct and Inverse Variations

Direct and Inverse Variations

Points to be Remember:-

Two quantities x and y are said to be in direct proportion or vary directly. If an increase (decrease) in x is followed by a corresponding increase (decrease) in y in such a manner that the ratio x remains

                                                                                           y

constant and positive

Points to be Remember:-

1. Two quantities x and y are said to be in inverse proportion or vary   inversely. If an increase in x is followed by a corresponding decrease in y (or vice versa) in such a manner that the product of the corresponding values of two quantities remains constant and positive. It means x and y vary inversely, if there exists a relation of the type xy = k between them, k being a fixed positive number.

2. Relation between time, distance and speed is written below:

           Speed = Distance 

                           Time