Respuesta :

Given:

The functions are:

[tex]f(x)=x+7[/tex]

[tex]g(x)=x^2-3[/tex]

To find:

The values f(g(4)), g(f(5)) and f(f(1)).

Solution:

We have,

[tex]f(x)=x+7[/tex]

[tex]g(x)=x^2-3[/tex]

(i) We need to find the value of f(g(4)).

[tex]f(g(4))=f((4)^2-3)[/tex]

[tex]f(g(4))=f(16-3)[/tex]

[tex]f(g(4))=f(13)[/tex]

[tex]f(g(4))=13+7[/tex]

[tex]f(g(4))=20[/tex]

Therefore, the value of f(g(4)) is 20.

(ii) We need to find the value of g(f(5)).

[tex]g(f(5))=g(5+7)[/tex]

[tex]g(f(5))=g(12)[/tex]

[tex]g(f(5))=(12)^2-3[/tex]

[tex]g(f(5))=144-3[/tex]

[tex]g(f(5))=141[/tex]

Therefore, the value of g(f(5)) is 141.

(iii) We need to find the value of f(f(1)).

[tex]f(f(1))=f(1+7)[/tex]

[tex]f(f(1))=f(8)[/tex]

[tex]f(f(1))=8+7[/tex]

[tex]f(f(1))=15[/tex]

Therefore, the value of f(f(1)) is 15.