Помогите решить 1) 10cos^2x-11sinx-2=0 2) 2sin^2x+13sin x cos x+6cos^2x=0 3) 3tg x-2ctg x+5=0 4) 7 sin2x+2=18cos^2x 5) 13sin2x+1=-5cos2x

1) 10(1-Sin^2x) -11Sinx -2 = 0 10 -10Sin^2x -11sinx -2 = 0 -10Sin^2x - 11Sinx +8 = 0 10Sin^2x +11sinx -8 = 0 решаем как квадратное D= b^2 -4ac = 121 -4*10*(-8) = 121 + 320= 441 a) Sinx = (-11+21)/20 = 1/2       б) Sinx = (-11 -21) /20 = -31/20(нет решений)  x = (-1)^n π/6 + πn, n Є Z 2) 2Sin^2x +13SinxCosx + 6Cos^2x = 0 |: Cos^2x 2tg^2x +13tgx +6 = 0 решаем как квадратное D = b^2 -4ac = 169 -4*2*6= 169 - 48 =121 a) tgx = (-13 + 11)/4 = -1/2 x = -arctg(1/2) +πn, n Є Z б) tgx = (-13 -11)/4 = -6 x = -arctg6 + πn, n Є Z 3)3tgx - 2Ctgx +5 = 0 | * tgx 3tg^2x -2 +5tgx = 0 решаем как квадратное  D = b^2 -4ac = 25 -4*3*(-2) = 25 + 24 = 49 a) tgx = (-5 + 7)/6 = 1/3 x = arctg(1/3) + πn, n ЄZ б) tgx = (-5-7)/6 = -2 x= -arctg2 + πk, k ЄZ 4)7Sin2x +2*1 = 18Cos^2x 14SinxCosx +2(Sin^2x + Cos^2x) -18Cos^2x = 0 14SinxCosx +2Sin^2x +2Cos^2x -18Cos^2x= 0 14SinxCosx +2Sin^2x -16Cos^2x= 0 7SinxCosx +Sin^2x -8Cos^2x = 0 | : Cos^2x 7tgx +tg^2x -8 = 0 tg^2x +7tgx -8 = 0 решаем как квадратное по т Виета а) tgx = -8 x = -arctg8 +πn, n ЄZ б)tg x = 1 x = π/4 + πk, k ЄZ 5) 26Sinx Cosx +Sin^2x + Cos^2x +5(Cos^2x - Sin^2x) = 0 26SinxCosx +Sin^2x + Cos^2x +5Cos^2x -5Sin^2x = 0 26SinxCosx -4Sin^2x +6Cos^2x = 0 13SinxCosx -2Sin^2x +3Cos^2x=0 | : Cos^2x 13tgx -2tg^2x +3 = 0 2tg^2x -13tgx -3 = 0 решаем как квадратное D = b^2 -4ac = 169 - 4*2*(-3) = 169 + 24= 193 tgx = (13 +-корень из 193)/4