SOLUTION: whats is the domain of f(x)= fourth root of x^2 + 3x

Algebra.Com
Question 212291This question is from textbook
: whats is the domain of
f(x)= fourth root of x^2 + 3x
This question is from textbook

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
whats is the domain of
f(x)= fourth root of x^2 + 3x
------------------------------------
f(x) = (x^2 + 3x)^(1/4)
---
To get Real Number results x^2+3x must be non-negative.
x^2+3x >= 0
---
x(x+3) >= 0
-------
Draw a number line.
Plot x = -3 and x=0
--
Test a value in each resulting interval to see where the solutions are:
If x = -10 you get -10(-7) >= 0, true, so solutions in (-inf,-3]
If x = -1 you get -1(2) >= 0, false
If x = 10 you get 10(13)>= 0, true, so solutions in [0,+inf)
===============================================================
Cheers,
Stan H.

RELATED QUESTIONS

Whats a square root function with the domain of {x|x ≥ 2} (answered by ikleyn)
Whats the domain of f(x)= {{{ sqrt( (x+2)/(x^2-8x+15) )... (answered by josgarithmetic)
find the domain of the function f (x) = square root of 12 − 3x^2 (answered by Edwin McCravy)
f(x) = x2 + 7, 0 ≤ x ≤ 2 whats the domain of the... (answered by solver91311)
What is the domain and the range of f(x) = square root of (3x -... (answered by josgarithmetic)
find the domain of the function f(x)=x+6-(square root of x+2)... (answered by longjonsilver)
How do you find the domain of the function f(x)= 3x+1/square root of x^2+x-2 (answered by josgarithmetic,ikleyn)
whats the domain and range of the function. f(x)=... (answered by MathLover1)
Whats the domain of... (answered by rapaljer)