Question

The function f: [0, 2π] ➝ [-1, 1] defined by f(x) = sin x is 

(a) One to one 

(b) Onto 

(c) Bijection 

(d) Cannot be defined

Answer 1

(b) Onto

For x = π/4, x = 3π/4, f(x) = 1/√2

So it is not one-to-one 

So it is an onto function