What is the domain and range of #f(x)=sqrt(4-x)#?

1 Answer
Apr 30, 2018

Answer:

Dom #f(x)={x in RR // x>=4}#

Range or Image of #f(x)=[0+oo)#

Explanation:

The expresion under square root must be positive or zero (square roots of negative number are no reals numbers). So

#4-x>=0#

#4>=x#

So the domain is the set of real numbers smaller or equal than 4

In interval form #(-oo,4]# or in set form

Dom #f(x)={x in RR // x>=4}#

Range or Image of #f(x)=[0+oo)#