Question

Упростить выражение

Answer 1

$frac{sinacdot sinbeta -cos(a-beta )}{ctga}=frac{sinacdot sinbeta -(cosacdot cosbeta +sinacdot sinbeta )}{ctga}=\\=frac{-cosacdot cosbeta }{frac{cosa}{sina}}=-frac{cosacdot cosbeta cdot sina}{cosa}=-cosbeta cdot sina$

Answer 2

(sinasinb-(cosacosb+sinasinb))/ctga