1)arctg1 = p/4
arcsin (sqrt3/2) = p/3
arccos(-1) = p
19/12 p
2)
a)3tgx = -3
tgx = -1
x = 3/4p + 2pn
x = -1/4p + 2pn, n принадлежит целым
б)
11cosx + 2 cos^2x +5 = 0
cos x =( -11 +- sqrt 121 - 40 )/4 = -1/2 или -5 cos x <= -1 <br>cos x = -1/2
x = +-2/3p + 2pn, n - целое
в)8sin^2x - 7sin2x + 6cos^2x = 0
6(sinx - cosx)^2 = 2sinx(cosx - sinx)
6(cosx - sinx) = 2sinx
6cos x = 8 sin x
8tgx = 6
tgx = 6/8
x = arctg(6/8)