The crossword solution for the term INVOLVING UP TO THIRD POWERS (MATHS) is CUBIC, which is a five-letter word. CUBIC equations involve terms that are raised to the third power, such as x^3 or y^3. CUBIC equations are polynomial equations of degree three, meaning that they have three terms with non-zero coefficients. These equations can be used to solve a variety of mathematical problems, from finding the roots of a function to determining the area of a shape.