linear function
Mathematical term for a function whose graph is a straight line, or more generally a function satisfying linearity properties.
A linear function becomes a straight line when graphed.
In this problem, we use the properties of linear functions.
一次関数 is often used in school mathematics for a linear function of the form y = ax + b, while 線形関数 is more common in higher mathematics and emphasizes linearity properties.
Antonym: a nonlinear function, which does not satisfy linearity.
Compound of 線形 (linear) and 関数 (function), a calque from English or German mathematical terminology.