Actualy you make some mistake in writing the question. Actually it is cos(-x) = cos x and sin(-x) = sinx. This is because of cosx is a even function (symmtric about y-axis) and sinx is odd function(anti-symmtric about y -axis). Thanks.
Last Activity: 10 Years ago
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.