Brain Dump

Exponent

Tags
math

Refers to the multiplication of a number by itself a certain number of times. We say a number \( x \) raised to the power \( y \) is equivalent to \( x^y = x \times x \times \dots \times x = \prod^{y} x \).

The special case of

  • \( y = 2 \) is known as squaring.
  • \( y = 3 \) is known as cubing.

Rules of Powers

Raising to the power can have different affects depending on the value of \( x \) and \( y \).

Table 1: Listing of possible \( x,y \) combinations and their equivalent forms.
LHSRHSExample
\( x^0 \)\( 1 \)\( 5^0 = 1 \)
\( x^1 \)\( x \)\( 5^1 = 5 \)
\( (\frac{x}{z})^y \)\( \frac{xy}{zy} \)\( (\frac{1}{2})^2 = \frac{1}{4} \)
\( (xz)^y = \)\( x^y z^y \)\( (2 \times 5)^2 = (2^2 \times 5^2) = 100 \)
\( x^a x^b \)\( x^{a+b} \)\( x^2 x^4 = x^6 \)
\( x^a / x^b \)\( x^{a-b} \)\( x^6 / x^2 = x^4 \)
\( (xa)b \)\( x^{ab} \)\( (x3)4 = x^{12} \)
\( x^{-a} \)\( \frac{1}{x^a} \)\( x^{-2} = 1 / x^2 \)
\( x^{1 / a} \)\( \sqrt{a}{x} \)\( x^{1 / a} = \sqrt[2]{x} \)
\( x^{b / a} \)\( \sqrt[a]{x^b} \)\( x^{2 / 3} = \sqrt[3]{x^2} \)

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