Question

find the domain
Q(y)=sqrt (y^2+1) - cuberoot (1-y)

Answer 1

Domain of y is all real numbers.
Explanation:
since the quantity y^2 is always positive ((y^2)+1)^(1/2) is always defined and since the a cube root is defined along all reals y can take any value. There does not exist a value of y that will make the function undefined

Answer 2

and what about in this case
4 / (x-9) - sqrt (x^3 -36)

Answer 3

x definitely can't equal 9 (since you would be dividing by 0)
and x^3 must be greater than 36 (since you can't have a negative in a square root
so x > 36^(1/3) and x \[\neq\] 9

Answer 4

thanx