Why is y² a nonlinear operator?

[spaghetti3451]

Homework Statement

Show that y² is non-linear.

Homework Equations

^O (ay1 +by2) = a ^O(y1) + b ^O(y2).

The Attempt at a Solution

No idea!

 

[HallsofIvy]

I have no idea what you mean by "^0".
Is it the operation (here, squaring)?

Then replace it by squaring: is $(ay_1+ by_2)^2= ay_1^2+ by_2^2$?

 

[spaghetti3451]

Thanks for the clue! I've solved the problem now!