Question

If f(x) = x2 and g(x) = 3x + 1, then g(f(2))= ?

Answer 1

The value of g[f(2)] = 13

Explanation:

Given functions:

f(x) = x²

g(x) = 3x + 1

Find:

The value of g[f(2)]

Computation:

f(x) = x²

By putting x = 2 in f(x)

f(x) = x²

f(2) = 2²

f(2) = 2 × 2

f(2) = 4

So the value of f(2) = 4

Value of f(2) putting in g(x)

g(x) = 3x + 1

g(x) = 3x + 1

g[f(2)] = 3[f(2)] + 1

We know that f(2) = 4

So,

g[f(2)] = 3[f(2)] + 1

g[f(2)] = 3[4] + 1

g[f(2)] = 12 + 1

g[f(2)] = 13

The value of g[f(2)] = 13