— Proportional to
The proportional-to sign (∝) states that two quantities scale together with a constant ratio: y ∝ x means y = kx for some constant k. It is the first step toward a full equation — finding k turns a proportionality into an equality.
Used in
- Newton's second law: a ∝ F (at fixed mass)
- Hooke's law: F ∝ x