Is y=x squared +2 a linear function

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

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. 

128/3reason being 5 and 1/3 = 16/316/3 • 2/3 = 32/31 and 1/3 = 4/3 32/3 • 4/3 this will equal 128/3