# Malus Law - Cosine squared term?

by Dart82
Tags: cosine, malus, squared, term
 P: 291 I simply tell my students that once upon a time, they wrote it as (sinx)^2, but lazy students kept leaving off the parenthesis and wrote sinx^2, sometimes meaning to take the sine of x, then square that answer; other times meaning to square the x first, then take the sine. To eliminate confusion, when they want the sin value to be squared, they put the squared symbol right next to sin $$sin^{2}x$$ So, to shorten $$(sinx)^2$$ write $$sin^{2}x$$ and to shorten $$sin(x^2)$$ write $$sinx^2$$ (although some people prefer those parenthesis are left in the latter case.)