EN
Book a Trial Class

SPM Mathematics Glossary

Variation, terms

Direct variationA relationship where one quantity increases as the other increases, written y = kx.Inverse variationA relationship where one quantity decreases as the other increases, written y = k/x.Joint variationA relationship where one quantity varies with two or more others at once.Direct variationA relationship where one quantity increases at a constant rate as another increases, y = kx.Inverse variationA relationship where one quantity decreases as another increases so their product is constant, y = k/x.Constant of variationThe fixed number k linking the quantities in a variation relationship.

Open the chapter →

Frequently asked questions

Which variation terms should I learn first?

Direct variation comes first, get comfortable writing y = kx and finding the constant of variation, k, from given values. Inverse variation follows the same pattern with y = k/x, and joint variation, which combines more than one relationship at once, is easiest to leave for last.

What is the most common confusion in the variation chapter?

Direct and inverse variation are mixed up most: in direct variation, y increases as x increases, but in inverse variation, y decreases as x increases. Students also sometimes forget that the constant of variation, k, stays fixed throughout a problem, it does not change once found from one pair of values.

How do variation terms appear in exam questions?

Questions usually give a table of values or a real-life situation and ask you to state the type of variation, find the constant of variation, and then express y in terms of x. Some questions ask you to use that equation to find an unknown value once the relationship is established.

Get help understanding any of these
One-hour paid trial · Same-day replyfrom RM50/hr
Book a Trial Class