1. в какой точке касательной к графику функций y=2x-lnx параллельна прямой y=x 2. выражение: 3sina*cos(n/2+a)-3/1+tg^2(n-a)

1)  f '(x)=2-1/х
угловой коэффициент прямой у=х равен 1, тогда 2-1/х=1⇒1/х=2-1=1
х=1       у(1)= 2-ln 1=2  
ответ: в точке(1,2)
2)  =3sinα×(-sin α)-3/(1+tg^2α)= - 3sin^2α-3×1/(1/cos^2α)= - 3sin^2α-3cos^2α= - 3 

1)
40 1/2 : (11 1/18 - 2 43/45) * 4 2/5 + 1 1/2 : 6 =
40 1/2 : (11 5/90 - 2 86/90) * 4 2/5 + 3/2 : 6 =
40 1/2 : (10 95/90 - 2 86/90) * 4 2/5 + 1/4 =
40 1/2 : 8 9/90 * 4 2/5 + 1/4 =
81/2 : 8 1/10 * 4 2/5 + 1/4 =
81/2 : 81/10 * 4 2/5 + 1/4 =
5 * 22/5 + 1/4 = 22 + 1/4 = 22 1/4

2)
(6 - 4 * 1/10) : (7 + 1 : 3/7) + (5 1/4 - 3 2/5) =
(6 - 4/10) : (7 + 7/3) + (5 5/20 - 3 8/20) =
(5 10/10 - 4/10) : 7 7/3 + (4 25/20 - 3 8/20) =
5 6/10 : 7 7/3 + 1 17/20 =
56/10 : 28/3 + 1 17/20 =
6/10 + 1 17/20 =
12/20 + 1 17/20 =
1 29/20 = 2 9/20

1)
40 1/2 : (11 1/18 - 2 43/45) * 4 2/5 + 1 1/2 : 6 =
40 1/2 : (11 5/90 - 2 86/90) * 4 2/5 + 3/2 : 6 =
40 1/2 : (10 95/90 - 2 86/90) * 4 2/5 + 1/4 =
40 1/2 : 8 9/90 * 4 2/5 + 1/4 =
81/2 : 8 1/10 * 4 2/5 + 1/4 =
81/2 : 81/10 * 4 2/5 + 1/4 =
5 * 22/5 + 1/4 = 22 + 1/4 = 22 1/4

2)
(6 - 4 * 1/10) : (7 + 1 : 3/7) + (5 1/4 - 3 2/5) =
(6 - 4/10) : (7 + 7/3) + (5 5/20 - 3 8/20) =
(5 10/10 - 4/10) : 7 7/3 + (4 25/20 - 3 8/20) =
5 6/10 : 7 7/3 + 1 17/20 =
56/10 : 28/3 + 1 17/20 =
6/10 + 1 17/20 =
12/20 + 1 17/20 =
1 29/20 = 2 9/20