Question

若代数式x的平方-6x+m可化为(x-n)的平方+1的形式,则n的平方-1/2m=?

Answer 1

解

x²-6x+m

=(x²-6x+9)+m-9

=(x-3)²+m-9

=(x-n)²+1

∴n=3,m-9=1

∴m=10,n=3

∴n²-1/2m

=3²-1/2×10

=9-5

=4