Involve the function definded by a Find f4 b Find f92 c Find

Involve the function definded by:

a. Find f(-4)

b. Find f(9/2)

c. Find f(9) - f(8). Caution. This is not equal to f(1)

Solution

a) for x= -4 f(x) = |x-5|

Therefore f(-4) = |-4-5| = |-9| = 9

b) for x= 9/2 = 4.5 f(x) = sqrt(2x)

Hence f(9/2) = sqrt(2*9/2) = sqrt(9) = 3

c)

First of all we will find f(9) . for x= 9 f(x) = 2x+1

hence f(9) = 2*9+1 = 19

Now we will find f(8). For x= 8 f(x) = sqrt(2x)

hence f(8) = sqrt(2*8) = sqrt(16) = 4

Therefore  f(9) - f(8) = 19- 4 = 15