Question

If f ∶ R → R and g ∶ R → R are two mappings defined as f(x) = 3x and g(x) = 3x2 + 9, then the value of (f + g) (2) is:
1. 21
2. 23
3. 27
4. 20

Answer 1

Correct Answer - Option 3 : 27

Calculation:

Given, f(x) = 3x, g(x) = 3x2 + 9

then, (f + g)(2) = f(2) + g(2)

= (3 × 2) + (3 × 22 + 9)

= 6 + 21

= 27

 ∴ The value of (f + g) (2) is 27