How many solutions exist for the equation arcsin(x) + arccos(y) = π/2?
None
One
Two
Infinite
Correct answer: Infinite
Solution
Since arccos(y)=pi/2-arcsin(x)=arccos(x), the equation forces y=x for every x in [-1,1], giving infinitely many solutions. The correct option is 'Infinite', not 'Two'.