Irrational number number to ratios of continuous magnitude. In his commentary on Book 10 of the "Elements", the Persian mathematician Al-Mahani (d. 874/884) examined and classified quadratic irrationals and cubic irrationals. He provided definitions for rational and irrational magnitudes, which he treated as irrational numbers. He dealt with them freely but explains them in geometric terms as follows: In contrast to Euclid's concept of magnitudes as lines, Al-Mahani considered integers and fractions as rational magnitudes, and square roots and cube roots as irrational magnitudes. He also introduced an arithmetical approach to the concept of irrationality, as he attributes the following to irrational
What Work Is with the working class or work in general. This helps place this collection within the tradition of working class poetry. For instance, besides work, love also is a major theme for Levine in this collection. "What Work Is" is a poem primarily written for his brother, and the difficulty of expressing that love. Often enough the theme of love is expressed in a subdued way and is shadowing the bolder themes most largely associated with work. The poems feature different types of work, some of which reflect the actual work experience of the author. For instance, the poems "Fear and