Answer: The required value is 36.
Step-by-step explanation: We are to find the value of the following expression for m = -2 and n = 4 :
[tex]m^2-2mn+n^2.[/tex]
Substituting the values m = -2 and n = 4 in the given expression, we get
[tex]m^2-2mn+n^2\\\\=(-2)^2-2\times (-2)\times 4+4^2\\\\=4+16+16\\\\=36.[/tex]
Thus, the required value is 36.