If f and g are real functions defined by f (x) = x2 + 7 and g (x) = 3x + 5, find each of the following (a) f (– 2) + g (– 1) (b) f (t) – f (– 2)

Solution:

Provided,

f and g are real functions such that and

(a)

Substitute in , we have

(i)

And,

Substitute in , we have

(ii)

Now add eq.(i) and eq.(ii),

We have,

(b)

Substitute in , we have

(i)

Now, consider the same function,

Substitute in , we have

(ii)

Now, subtract eq.(i) with eq.(ii),

We have,