That stand for (power to), since I don't have the superscript key on my computer. Do you know when you see parabola equation and it says y= x^2 (y equals x squared?). ^ is my shortcut for (raised to the power).
Just like x^3 (x raised to the 3rd power), I do not have access to special math symbols on my computer such as "squared", "cubed" "square root" or "cube root". My computer is old and every time I try to add math add-ins, they never work. I guess my computer is too old.