How do you find the domain and range for #y= -2x+3, x>0#?

1 Answer
Aug 3, 2015

Domain: #(0, +oo)#
Range: #(-oo, 3)#

Explanation:

The problem actually gives you the domain of the function as being described by #x>0#.

More specifically, the domain of the functioncannot include negative values of #x#, as well as #x=0#.

This means that the domain of the function will be #(0,+oo)#.

Now for the range of the function. SInce #x# is always positive, the term #-2x# will always be negative. You can find the range of the function by using #x=0# to find the maximum value #f(x)# cannot take

#f(0) = -2 * 0 + 3 = 3#

This means that the function's range will be #(-oo, 3)#, since #f(x)# will produce a value smaller than #3# for any #x# belonging to the #(0, +oo)# domain.