Originally Posted by

**TomSmith** This seems like a a pretty basic problem, but i've been revising maths all day and i can't get my head round it.

When something appears in an equation as '-a²' does that mean '-a*-a' or '-(a²)', and how can you tell the difference. I had thought it meant the former (when using things like the quadratic formula), but thinking about it, in equations such as using the cosine rule, I use the latter form all the time. I have an exam tomorrow and I don't want to make a stupid mistake.

**Th**anks in advance for any help offered.