Question

Determine all points of intersection: y=cosx and y=sinx in the first quadrant

Answer 1

There is just one value in the first quadrant where:
sin x = cos x = $\frac{ \sqrt{2} }{2}$
The point is ($\frac{ \sqrt{2} }{2} , \frac{ \sqrt{2} }{2}$) and x=45°=π/4