Exponentiation
Common term for three tightly linked concepts:
- Powers
- Roots
- Logarithms
Powers
$base^{exponent} = power$
Roots
$\sqrt[exponent]{power} = base$
Logarithms
$log_{base}(power) = exponent$
In General Form
$x^{y} = z \Leftrightarrow \sqrt[y]{z} = x \Leftrightarrow log_x(z) = y$
Example
$x = 10$
$y = 3$
$z = 1000$
$10^3 = 1000 \Leftrightarrow \sqrt[3]{1000} = 10 \Leftrightarrow log_{10}(1000) = 3$
Inverse Exponents?
$x^{-y} = \frac{1}{x^y}, x \neq 0$
Hating Those Roots?
$\sqrt[y]{z^x} = z^{\frac{x}{y}}$
Complex Numbers
$\abs{z} = \abs{zhat}$
$\abs{z} = \sqrt{a^2 + (-b)^2} = \sqrt{a^2 + b^2} = \abs{zhat}$
$z * z^{-1} = 1$
$(a + ib)(u + iv) = aU - bv + i(av + ub) = 1 = 1 + 0i$
$au - bv = 1$
$au + ub = 0$
$au -b(-\frac{ub}{a}) = 1$
$v = -\frac{ub}{a}$
$u(a + \frac{b^2}{a}) = 1$
$u(\frac{a^2 + b^2}{a}) = 1$
$u = \frac{a}{a^2 + b^2}$
$v = -\frac{b}{a^2+b^2}$