Логарифмы

a > 0, a ≠ 1, b > 0, x > 0, y > 0

logab = c

ac = b

alogab = b

loga1 = 0

logaa = 1

lga = log10a

lna = logea

1) logaxy = logax + logay

2) loga xy = logax - logay

3) logaxn = n logax

4) loganx = 1n logax

5) loganxm = mn logax

6) logab= logcb logca

7) logab= 1 logba

8) alogcb = blogca

Метод рационализации при решении неравенств:

1) log f(x) g1(x) ≤ log f(x) g2(x)

(f(x) − 1)(g1(x)g2(x)) ≤ 0

2) log f1(x) g1(x) ⋅ log f2(x) g2(x) > 0

(f1(x) − 1)(g1(x) − 1)(f2(x) − 1)(g2(x) − 1) > 0

Вверх