In differential equations class, they had...
x = \frac{dy}{dx}
The student cancelled the d's, and then multiplied both sides by x and added "+C". That's y = x^2 + C. Argued his answer was correct and was only missing an insignificant coeficient and should get full marks.
I'm doing reading course on Projective Geometry.
I was presented this question (in the textbook, not homework):
In P_2 R, let A, B, and C be points on a line L and let A', B', and C' be points on a line L'. Prove there exists points S_1, S_2 and S_3, and lines l_1 and l_2 such that...
I took Graph Theory last term. I enjoyed it very much.
No textbook though. Mostly his lecture notes and browsing books and internet for assignments.
My main issue was all the definitions. So many of them.
Can you check and make sure you wrote this down correctly.
Also, I assume x1 means x_1.
Also, x_1 can be anything I want?
Every detail to a question is important. There is no such thing as text talk in mathematics. ;)
I can hardly call it a simplication if it has another double factorial. I would just say it's another way to write it. It's equivalent.
The obvious answer to something that is equivalent...
(n!!-1)!