Saved Bookmarks
| 1. |
prove sin ^2 + cos^2=1 . |
| Answer» Consider a right angled triangle ABC in which angle B=90° and angle A=€°. Let AB=x units, BC=y units and AC=r units. Then by Pythagoras theorem x^2+y^2=r^2 (y/r)^2+(x/y)^2=(y^2/r^2+x^2/r^2) (x^2+y^2)/r^2 = r^2/r^2 =1 Sin^2€+cos^2€=1 | |