Question

найдите ctg a, если
$\frac{4sina - 3cosa}{2cosa + \ \: 3sin \: a} = 3$..

Answer 1

$\frac{4sina \: - 3cosa}{2cosa \: + 3sina} = 3 \\ 4sina \: - 3cosa \: = 6cosa + 9sina \\ - 5sina \: = \: 9cosa \\ \frac{cosa}{sina} = - \frac{5}{9} \\ ctga = - \frac{5}{9}$