Is y=x squared + 2 a linear function

Y=x^2 + 2 is not a linear function. This is because the x has power. If it was only x then it would be linear function. So x^2 + 2 is quadratic function. However if it was x^3, it would be quadratic; it would be cubic. Therefore fore only x squared is quadratic.

No, this would not be a linear function. Being linear means it creates a straight line, but this function has an x squared. Anytime x^2 is in a function, the graph is a u shape, called a parabola. A simple linear function is y=x : D