What is the range if f(x) = 3x - 9 and domain: -4,-3,0,1,8?

2 Answers
Jul 24, 2018

#y in{-21,-18,-9,-6,15}#

Explanation:

#"to obtain the range substitute the given values in the "#
#"domain into "f(x)#

#f(-4)=-12-9=-21#

#f(-3)=-9-9=-18#

#f(0)=-9#

#f(1)=3-9=-6#

#f(8)=24-9=15#

#"range is "y in{-21,-18,-9,-6,15}#

Jul 24, 2018

Range = #{-21, -18, -9, -6, +15}#

Explanation:

Here we have a lineal function #f(x) = 3x-9# defined for #x={-4,-3,0,1,8}#

The slope of #f(x)=3 -> f(x)# is linear increasing.

Since #f(x)# is linear increasing, its minimum and maximum values will be at the minimum and maximum values in its domain.

#:. f_min = f(-4) = -21#

and #f_max = f(8) = 15#

The other values of #f(x)# are:

#f(-3) = -18#
#f(0) = -9#
#f(1) = -6#

Hence the range of #f(x)# is #{-21, -18, -9, -6, +15}#