How do you find the domain of #y=(2x)/(-x-5)#?

1 Answer
Mar 9, 2017

#{x: x inRR,x!=-5}#

Explanation:

The domain of a function is all real values that x can have without causing the function to be undefined.

Here y will be undefined if the denominator equals zero.

#rArr-x-5=0rArr-x=5rArrx=-5#

Hence the domain is ALL real values of x except x ≠ -5

Which may be expressed in #color(blue)"set builder notation"# as

#{x:x inRR,x!=-5}#