As given by the question
There are given that the function:
Now,
(a):
To find the value of f(-2), put r = -2 into the given function:
Then,
Hence, the value of f(-2) is -5.
(b):
To find the value of f(98), put r = 98 into the given function:
Then,
Hence, the value of the f(98) is 5.
Now,
(c):
To find the value of f(x-2), put r = x-2 into the given function:
So,
Hence, the value of f(x-2) is shown below;