Michelle needs to convert the function f (x) = x2 - 10x + 31 to vertex form, fx) = (x - 1) 2 + k, in order to find the minimum.

When she does this, what is the value of k in the vertex form of function?

26

56

31

6

To find k

You can do

C-a ((b/2) ^2))

This is because when you complete the square you have the c value that you have initially minus the new c value which is found by (b/2) ^2 and if you factored a number out then multiply it to that.

So in this case

31 - 1 (10/2) ^2

31 - (5) ^2

31-25

6