Complex numbers in mod-arg form ("cis") Greetings, I'm learning about the mod-arg form. I find it fairly easy when I come across simple radians that relate to the two special triangles like pie/3, pie/4 and pie/6. But when the radians become a little bit more complicated like 3pie/4 I'm in the foetal position. This equation in particular; "2cis3pie/4" I only get to 2cos 135degress + i2 sin 135degrees I can't simplify it down. I know that 3pie/4 is 135degrees but i can't convert it to a fraction. If anyone could help me with a method to solve more complicated radians that would be much appreciated.