Question

Знайти похідну функцій1)y=lnsinx 2)y=lncosx3)y=lntgx 4)lnctgx

Answer 1

1) y = lnsinx

$y' = (lnsinx)' = \frac{1}{sinx}*sin'x = \frac{cosx}{sinx} = ctgx$

2) y = lncosx

$y' = (lncosx)' = \frac{1}{cosx}*cos'x =- \frac{sinx}{cosx} = - tgx$

3) y = lntgx

$y' = (lntgx)' = \frac{1}{tgx}*tg'x = \frac{cosx}{sinx}*\frac{1}{cos^2x} = \frac{1}{sinx*cosx}$

4) y = lnctgx

$y' = (lnctgx)' = \frac{1}{ctgx}*ctg'x = \frac{sinx}{cosx}*(-\frac{1}{sin^2x}) = - \frac{1}{sinx*cosx}$