Question

Draw the graph of function f(x) = cos x. Check injectivity and surjectivity .write its domain and range.?

Answer 1

Step-by-step explanation:

Solution



Correct option is

C

neither injective nor surjective

Injectivity : We know that f(0)=cos0=1 and f(2π)=cos2π=1.

So, different elements in R may have the same image. Hence, f is not an injection.

Surjectivity : Since the values of cosx lie between −1 and 1, it follows that the range of f(x) is not equal to its co-domain. So, f is not a surjection.