Реферат: Основы математики

¦ 1 + tga*tgb ¦ 1 - tga*tgb ¦

+-----------------------+-T----------------------+----¬

¦ Ctga*ctgb + 1 ¦ Ctga*ctgb - 1 ¦

¦Ctg(a-b) =-------------- ¦ Ctg(a+b) = ------------- ¦

¦ Ctg a - ctg b ¦ Ctg a + ctg b ¦

+-----------------------T-+---------------------T------

¦Sin 2a = 2*Sin a*Cos a ¦ Cos2a = Cos2a - Sin2a ¦

+-----------------T-----+--------------T---------

¦ 2*tg a ¦ Ctg2a - 1 ¦

¦tg 2a = -------- ¦ Ctg 2a = --------- ¦

¦ 1 - tg2a ¦ 2*Ctg a ¦

L-----------------+---------------------

Sin a * Cos b = 0,5*[Sin(a-b) + Sin(a+b)]

Sin x + Sin y = 2Sin 0,5(x+y) * Cos 0,5(x-y)

Sin x - Sin y = 2Cos 0,5(x+y) * Sin 0,5(x-y)

Cos x + Cos y = 2Cos 0,5(x+y) * Cos 0,5(x-y)

Cos x - Cos y = -2 Sin 0,5(x+y) * Sin 0,5(x-y)

Cos a * Cos b = 0,5[Cos(a-b) + Cos(a+b)]

Sin a * Sin b = 0,5[Cos(a-b) - Cos(a+b)]

---------------------------T---------------------------------¬

¦ Sin(x-y) ¦ Sin(x+y) ¦

¦tg x - tg y = ----------- ¦ tg x + tg y = ----------- ¦

¦ Cos x Cos y ¦ Cos x Cos y ¦

+--------------------------+--T------------------------------+

¦ Sin(x-y) ¦ Sin(x+y) ¦

¦Ctg x - Ctg y = ------------ ¦ Ctg x + Ctg y = ----------- ¦

¦ Sin x Sin y ¦ Sin x Sin y ¦

L-----------------------------+-------------------------------

Sin 3x = 3Sin x - 4Sin3x 2tg x