Question

Ребята, помогите с дискретной математикой.

Answer 1

4)
(а^(-1/3) + a^(1/2))^7 =
а^(-1/3*7+1/2*0)*1+
а^(-1/3*6+1/2*1)*7+
а^(-1/3*5+1/2*2)*7*6/2+
а^(-1/3*4+1/2*3)*7*6/2*5/3+
а^(-1/3*3+1/2*4)*7*6/2*5/3*4/4+
а^(-1/3*2+1/2*5)*7*6/2*5/3*4/4*3/5+
а^(-1/3*1+1/2*6)*7*6/2*5/3*4/4*3/5*2/6+
а^(-1/3*0+1/2*7)*7*6/2*5/3*4/4*3/5*2/6*1/7=
=sum a^(-1/3*к+1/2*(7-k))*7!/(k!(7-k)!)
-1/3*к+1/2*(7-k) = 1
-1/3*к+7/2-k/2 = 1
5/2=5k/6
k=3
a^(-1/3*к+1/2*(7-k))*7!/(k!(7-k)!) = a^(-1/3*3+1/2*(7-3))*7!/(3!(7-3)!) = a^1*35
ответ 35

1) х=1/3*arctg(корень(3)/3)=1/3*pi/6=pi/18
3) х=1/3*arctg(1/3)