Given the functions fx 5x 1 and gx square root x find the
Given the functions f(x) = -5x - 1 and g(x) = square root x, find the following functions and their domains: Write the domains using interval notation. If the quantities do not exist, write \"undefined\" in the blank provided. You have 3 attempt(s) remaining before you will receive a new version of this problem.
Solution
f(x) = -5x -1 , g(x) = x
(f o g)x = f(g(x))
==> (f o g)x = f(x)
==> (f o g)x = -5x -1
Hence (f o g)x = -5x -1
(g o f)x = g(f(x))
==> (g o f)x = g(-5x -1)
==> (g o f)x = (-5x -1)
Hence (g o f)x = (-5x -1)
Domain of (f o g)x ==> value under square root is greater than zero
==> x >= 0
Hence domain is [0 , )
Domain of (g o f)x ==> value under square root is greater than zero
==> (-5x -1) >= 0
==> 5x + 1 <= 0
==> 5x <= -1
==> x <= -1/5
Hence domain of (g o f)x = (- , -1/5]
