Positive exponent? An index would imply that the base, x, had a fractional exponent.
My Dear Aunt Sally used to say, "If there's a negative exponent in your face, then flip your base!"
In other words, if the exponent is negative, take the reciprocal of the base, x → [tex] \frac{1}{x} [/tex] and change the exponent to positive.
Therefore: [tex] x^{-3} = \frac{1}{x^3} [/tex]
I have cross the fraction bar line change the exponent sign.
