Find the number of real solutions of the equation sin(pi*x) + x² + 1 = 2x.
0
1
2
infinitely many
Correct answer: 1
Solution
The equation becomes sin(pi*x) = -(x-1)². At x = 1 both sides equal 0; for any other x the right side is strictly negative while equality forces a unique match, so there is exactly one solution.