How do you find domain for y = sqrt((4+x) / (1-x) ) ?

1 Answer
Sep 27, 2015

Domain {x:RR, -4<=x<1}

Range {y:RR, y>=0]

Explanation:

For real y, 4+x>=0, x>=-4; and 1-x>0, or, x<1

The domain is therefore {x:RR, -4<=x<1}

For range, at x=-4, y is 0 and as x increases from -4, y remains positive and as x approaches 1, y->+oo. Hence Range would be

{y:RR, y>=0}