Use the Pythagorean Theorem Identities. Find cotθ if cosθ=1/7 and sinθ<0 .

Because greater means best, and you have to start with the best!

Just kidding, the real answer is that it makes it more simple to count up on the number line. If you start with the higher number, you don't have to count up as many places because you count up whatever the value of the smaller number is