The Purplemath Forums

I was graphing a function today and was wondering why you devide the exponent on the highest degree on top by the exponent on the highest degree on the bottom to get the horizontal asymptote if the degrees are equal in numerator and denominator... I understand that this works and that we can get the...

In my math book there is a question: -25^3/2 and (-27)^4/3.
I would think it is impossible to take roots of a negative but my math book apparently says that the answer is -125 and 81.
Can you help me understand this?

With the problem 2/(1-i) * (1+i)/(1+i),

since (1+i)/(1+i) cancels out to a one, if you multiply one times 2/(1-i), don't you just get 2(1-i)??
For some reason, the answer is l+i.
Why can't you just make (1+i)/(1+i) equal one?