Let f be the function defined by the equation f(x) =8x-2

Question

Find f(6) 

f (1.5)

f (0)

f (a)

f(a+1) 

Answer 1

Anything you see in parenthesis, substitute it for x.

 

f(6) = 8(6) - 2

      = 42 -2

      = 40

 

f(1.5) = 8(1.5) - 2

         = 12 - 2

         = 10

 

f(0) = 8(0) - 2

       = 0 - 2

       = -2

 

f(a) = 8a - 2

 

f(a+1) = 8(a + 1) - 2

           = 8a + 8 - 2

           = 8a + 6

Answer 2

Evaluate f(x) for f(6)  means find the value of f(x) at 6.

You plug 6 into the equation for x and evaluate it.

 

Like this:

f(x) = 8x - 2

      = 8(6) - 2

      = 48 - 2  = 46

 

Do the rest by putting in 1.5, 0, a, and (a+1)

into the equation for x.