If the real number m, n satisfies the relation m + n = 4, find the minimum value of m ^ L2 + n ^ 2

If the real number m, n satisfies the relation m + n = 4, find the minimum value of m ^ L2 + n ^ 2

Because m + n = 4
So m = 4-N
So m ^ 2 + n ^ 2 = (4-N) ^ 2 + n ^ 2
=2n^2-8n+16
=2(n-2)^2+8
If and only if M = n = 2, the minimum value of the original formula is 8