1.

If f : R → R,f(x) = cos (x + 2), is f-1 exists.

Answer»

Given function

f : R → R, f(x) = cos (x + 2).

Putting x = 2π

f(2π) = cos (2π+ 2)

= cos (2)

Putting x = 0

f(0) = cos (0 + 2) = cos 2

Here, only one image is obtained for 0 and 2π.

So, ‘f’ is not one-one.

Thus, ‘f’ is not one-one onto.

Hence, f-1 : R → R does not exist.



Discussion

No Comment Found