I'm so glad I finally found a video without comments disabled, because I can finally express how amazing these videos are: these are life savers! Thank you so much for all your work, it's truly appreciated.
arcsin(-1) = 270. You may have used your calculator and got the answer as -90. Whilst this is correct, there are an infinite amount of correct answers as the trigonometric functions go on forever (in the x-direction).
