Posted by Gregory on .
Find the domain:
Algebra - Functions -
all polynomials have domain of (-∞,+∞)
√u has domain u >= 0
rational functions have domains which exclude where the denominator is zero.
Keeping that in mind, I'll do (b), and the rest should be easy.
√(x+3) needs x+3 >= 0, or x >= -3
the domain also excludes x=±6, since then 5x^2-180=0, and you cannot divide by zero. -6 is already excluded by the √, so the domain is [-3,6)∪(6,∞)