5,4*x=3,78
X=3,78:5,4
X=0,7
sqrt{(5-3sqrt{2}cosx-(cosx)^2)}+sqrt{3}sinx=0
sqrt{(5-3sqrt{2}cosx-(cosx)^2)}=-sqrt{3}sinx
(sqrt{(5-3sqrt{2}cosx-(cosx)^2)})^2=(-sqrt{3}sinx)^2
5-3sqrt{2}cosx-(cosx)^2=3(sinx)^2
5-3sqrt{2}cosx-(cosx)^2=3(1-(cosx)^2)
5-3sqrt{2}cosx-(cosx)^2=3-3(cosx)^2)
2-3sqrt{2}cosx+2(cosx)^2=0 | t=cosx
2t^2-3sqrt{2}t+2=0
D=18-4*2*2=2
t1=sqrt{2}
t2=sqrt{2}/2
cosx=sqrt{2} -решений нет, т.к. |cosx|<=1, a sqrt{2}>1
cosx=sqrt{2}/2
x=+-П/4+2Пn, n принадлежит Z
B2=1/3
b1+b3=10/9
bn=b1q^(n-1)
b2=b1q
b3=b1q^2
b1q=1/3 b1=1/3q
b1+b1q^2=10/9 1/3q+q/3=10/9 6=10q q=3/5 b1=5
b4=5*(1/5)^3=5*1/125=1/25
b2*b4=1/3*1/25=1/75
Приложение калькулятор в столбик