Logarifmlar

Logarifm — «asosni qanday darajaga ko'tarsak, berilgan son chiqadi?» degan savolga javob:

$\log_a b = c \iff a^c = b \qquad (a > 0,\; a \ne 1,\; b > 0)$

Masalan, $\log_2 32 = 5$, chunki $2^5 = 32$; $\log_{\frac{1}{3}} 27 = -3$, chunki $\left(\tfrac{1}{3}\right)^{-3} = 27$. Mana shu ta'rifning o'zi ko'p tenglamalarni yechadi.