What is direct, inverse, and partitive proportion?

Question

first trig homework, now this! i forgot what this meant, and my mom threw away my notes, so...yeah. sux. can u also show examples? EXAMPLES EXAMPLES EXAMPLES...

Answer 1

Direct proportion:
a/b = k(c/d)
Charles Law:V2/V1 = T2/T1
5/2 = 10/4
inverse proportion:
a/b = (1/k)(b/c)
Boyle's Law
V2/V1 = P1/P2

Never heard of partitive proportion before, & search turned up a lot of ambiguous articles. I THINK it goes like this:
a =bc/d