1. if f(x)=1-x^2 and g(x)=1-x which is the rule of function (f-g)(x)
A. 1+x
B. -x^2+x
C. -x^2-x+2
D. x^3-x^2-x+1

2. For the pair of functions, f and g, find (f•g)(x) and (g•f)(x).
f(x) = 3+x, g(x) = x^2 + 1
PLEASE HELP

Respuesta :

QUESTION 1

If f(x)=1-x² and g(x)=1-x,

Then,

(f-g)(x)=f(x)-g(x)

This implies that,

[tex]( f - g)(x) = 1 - {x}^{2} - (1 - x)[/tex]

[tex]( f - g)(x) = 1 - {x}^{2} - 1 + x[/tex]

We simplify to get,

[tex]( f - g)(x) = - {x}^{2} + x[/tex]

The correct choice is B.

QUESTION 2

Given:

f(x)=3+x

and

[tex]g(x) = {x}^{2} + 1[/tex]

[tex](f\circ g)(x)=f(g(x))[/tex]

[tex](f\circ g)(x)=f( {x}^{2} + 1 )[/tex]

[tex](f\circ g)(x)=3 + {x}^{2} + 1[/tex]

[tex](f\circ g)(x)= {x}^{2} +4[/tex]

Also,

[tex](g\circ f)(x)=g(f(x))[/tex]

[tex](g\circ f)(x)=g( 3+ x)[/tex]

[tex](g\circ f)(x)= {(3 + x)}^{2} + 1[/tex]

[tex](g\circ f)(x)= 9 + 6x + {x}^{2} + 1[/tex]

[tex](g\circ f)(x)= {x}^{2} + 6x + 10[/tex]