>>509791352 (OP)>e^(pi*i)+1=0 - I have no idea what it meansIn maths, solutions to equations are real numbers until you start using complex numbers with include the 'imaginary' number i to get around the fact some functions don't have solutions using only real numbers (e.g. x^2 +1 = 0).
In complex analysis, it can be shown that y = e^ix is equivalent to y = cos(x) + i*sin(x), giving the usually only exponential function a kind of circular interpretation once we include the imaginary axis.
The argument, x, is just what angle we want to look at (in radians). And an angle of pi is equivalent to 180 degrees clockwise from the origin.
Thus, e^i*pi evaluates to cos(pi) + i*sin(pi) which is like cos(180) + i*sin(180) which equals -1 + i*0 giving us the famous relation.
It's maybe a bit easier to follow if you keep in mind that cos refers to a horizontal value of the point, sin the point's vertical value, and x is the angle of rotation. to have a radius pointing towards the point (labelled in green in picrel).
