Here's the question you clicked on:
elegant11
Find the values of x for which the equation cos x = –1 is true. Let k represent an integer.
these are the answer choices 2pik pi/2 + 2k pi + 2pik 3pi/2+ 2pik
isn't there k in the equation? which we're supposing as an integer?
i have no idea. i don't even know where to begin :(
hold on.. and check the question again if it is the same u've written?
Find the values of x for which the equation cos x = –1 is true. Let k represent an integer.
I'm gonna go now, will tell u after solving..
Well when is cosx = -1 the first time in the circle? At π (because x=180 degrees)... right? So now when does it occur again, well it doesnt happen again until we go around in a full circle. So another 2π and this will happen indefinitely for any integer k. So the answer is: π + 2πk