Question

oblicz:

a) cos110 : cos70 - tg160 * tg70

b) cos(90+40) : sin(180-40) + tg(180-30) * tg60

Answer 1

a) cos110 : cos70 - tg160 * tg70 =

cos110*: cos(180* - 110*) - tg(90* + 70*) * tg70* =

cos110* : (-cos110*) -(-ctg70*) * tg70* = - 1 + 1/tg70* * tg70* = 1 + 1 = 2

 

b) cos(90+40) : sin(180-40) + tg(180-30) * tg60 =

-sin40* : sin40* + (-tg30*) * tg60* = - 1 - √3/3 * √3 = -1 - 3/3 = -1 - 1 = -2