How do you find the value of #f(1/2)#, if #f(x)=3x-4#?

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Answer 1 · 2017-05-03T19:15:44

See the solution process below:

Substitute #color(red)(1/2)# for each occurrence of #color(red)(x)# in the function #f(x)# and calculate the result:

#f(color(red)(x)) = 3color(red)(x) - 4# becomes:

#f(color(red)(1/2)) = (3 xx color(red)(1/2)) - 4#

#f(color(red)(1/2)) = 3/2 - 4#

#f(color(red)(1/2)) = 3/2 - (2/2 xx 4)#

#f(color(red)(1/2)) = 3/2 - 8/2#

#f(color(red)(1/2)) = (3 - 8)/2#

#f(color(red)(1/2)) = -5/2#

Answer 2 · 2017-05-03T19:18:38

#f(1/2)=-5/2#

Sub #x=1/2# into the function,

#f(1/2)=3(1/2)-4#

#f(1/2)=3/2-4#

#f(1/2)=-5/2# or #-2.5#