Logarithmic Functions (Edexcel A-Level Mathematics): Flashcards

It finds the power of $3$ that equals $27$.

As 'log base 3 of 27.'

$\log_3(27) = 3$.

Base $10$ is assumed if no base is written.

If and only if $a^x = y$, where $a > 0$ and $a \neq 1$.

It's often written simply as $\log(y)$.

It's $\log_e(y)$, where $e \approx 2.718$.

$\log_a(xy) = \log_a(x) + \log_a(y)$.

$\log_a(x^n) = n \cdot \log_a(x)$

$\log_a(x) = \log_b(x) / \log_b(a)$ for any base $b$.