What is the domain and range of #Y(x)= -2 sqrt(-x) + 20#?

1 Answer
Oct 3, 2016

Domain: #(-oo, 0): x in RR#
Range: #(-oo, 20): Y(x) in RR#

Explanation:

#Y(x) =-2sqrt(-x)+20#

Assume #Y(x) in RR ->x<=0 : x in RR#

Hence domain of #Y(x)# is #(-oo, 0)#

Since the coefficient of the radical is negative #(-2)#, #Y(x)# has a greatest value of #20# at #x=0#. #Y(x)# has no finite least value.

Hence the range of #Y(x)# is #(-oo, 20)#