SOLUTION: given the functions f(x)=x+2 and g(x)=x^2, determine all values of x for which f(g(x))=g(f(x)).

Algebra.Com
Question 1194123: given the functions f(x)=x+2 and g(x)=x^2, determine all values of x for which f(g(x))=g(f(x)).
Answer by ikleyn(52780)   (Show Source): You can put this solution on YOUR website!
.
given the functions f(x)=x+2 and g(x)=x^2, determine all values of x for which f(g(x))=g(f(x)).
~~~~~~~~~~~~~~~~~

Left side of this equation is

    f(g(x)) = g(x) + 2 = x^2 + 2.


Right side of this equation is

    g(f(x)) = (f(x))^2 = (x+2)^2 = x^2 + 4x + 4.


So, this equation  f(g(x))=g(f(x))  takes the form

    x^2 + 2 = x^2 + 4x + 4.


Cancel the terms x^2 in both sides; keep the term with x in right side; collect constant terms in left side

    2 - 4 = 4x

      -2  = 4x

      -1/2  =  x.


ANSWER.  x = -1/2.

Solved.



RELATED QUESTIONS

Given the functions f(x) = x + 2 and g(x) = 3^x , Determine all values of x for which... (answered by greenestamps)
8. a) Given the functions f(x) = x + 2 and g(x) = 3^x, determine an equation for (f ∘... (answered by Edwin McCravy)
Please help me with this question. Thank you! a) Given the functions f(x) = x + 2 and... (answered by solver91311,MathLover1)
Find all real values of x for which f(x) = g(x) F(x) = x^2 , G(x) = 12... (answered by ewatrrr)
For each pair of functions, find f(g(x)) and g(f(x)).... (answered by Gogonati)
Given functions f and g, determine the domain of f+g, f(x)=4x/x-8,... (answered by nerdybill)
Let C(x)=(1+x^2)^3. Find the functions f and g so that C(x)=(f o g)(x) is true for all... (answered by stanbon)
given the functions f(x) = 1-3x^2 and g(x) = sqrtx-1, find the functions (f+g) , (f-g),... (answered by josgarithmetic)
If {{{f(x)=(x)^2-4}}} and g(x)=x, find values of x for which... (answered by ewatrrr)