Question

Va rog raspuns!!!(Trigonometrie)

Answer 1

tg a + tg b =$\frac{sina}{cosa}+ \frac{sinb}{cosb}= \frac{sina*cosb+sinbcosa}{cosa*cosb}= \frac{sin(a+b)}{cosa*cosb}.$
tg a - tgb =$\frac{sina}{cosa}- \frac{sinb}{cosb}= \frac{sina*cosb-sinbcosa}{cosa*cosb}= \frac{sin(a-b)}{cosa*cosb}.$