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 (3) + g (– 5) (b) f(½) × g(14) (c) f (– 2) + g (– 1)

Solution:

Provided,

f and g are real functions such that and

(a)

Now substitute in , we have

(i)

And,

Now, substitute in , we have

(ii)

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

We have,

(b)

Now, substitute in , we have

(i)

And,

Substitute in , we have

(ii)

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

We have,