1. What are the other names for an index ?

An index is sometimes called a power or exponent.

2. What is the value of x1?

The value of xis x.

The value of any number or variable to the power of 1 is equal to the number or variable itself.

3. Is it possible to have a negative index?

Yes. A negative index involves taking the reciprocal of the variable. e.g. x−4 = 1x4
This is normally studied in more detail in later years.