Question

for what values of x is this expression defined √x+4÷√1-x?
please help answer...

Answer 1

if yo mean
$\frac{ \sqrt{x+4} }{ \sqrt{1-x} }$

remmber, yo can't divide by 0 so √(1-x)≠0 and therefor 1-x≠0 and x≠-1

and we can't have a square root of aneagtive
1-x≥0
1≥x

but also
√(4+x)
4+x≥0
x≥-4

so

-4≤x and x≤1 and x≠-1

so
domain is all real numbers from -4 to 1 excluding -1
or
[-4,-1) U (-1,1]