Mark the correct alternative in the following:

If then f(x + y) f(x – y) is equals to

Mark the correct alternative in the following:

If then is equal to

Mark the correct alternative in the following:

If f(x) = cos (log x), then value of is

Mark the correct alternative in the following:

If then f(2) is equal to

Mark the correct alternative in the following:

Let f : R → r be defined by f(x) = 2x + |x|. Then f(2x) + f(-x) – f(x) =