What is the little 3 in maths called?

Answer 1

It can be an exponent (if you find it after your number) or a root (if you find it in the bend of the square root sign. In the square root sign that goes over a number, if there is nothing in the bend (or the "V") of the sign, then the sign indicates the square root of the number under the "roof" of the sign. If there IS a number in the "V", for instance 3, it means the cube root of the number under the roof; a 4 in the V means the fourth root, and so on. Think of a number under the roof of the square root sign as yielding the opposite value from the same number with an exponent of 2. If you put a number with an exponent of 2 under a square root sign, the result will be your original number: in other words, the square root of 2 squared is 2. If you want to express a square root without the square root sign, you could simply give your number an exponent of the RECIPROCAL of two (e.g. 9-1/2), which equals 3. In words, this means nine to the one-half power equals the square root of nine, equals 3.

x2 -- the 2 is called a subscript which here means the second value of x, usually after being changed by a function, or perhaps it indicates the second value of x that will be used in your calculation

x2 -- the 2 is called a superscript (or "power") which here means x to the second power (x squared).