19/08/22 23:49:08.15 CKZgVpHz0.net
1.
b=3a-1 (1/3≦a<1,1<a)
b=-a^3+3a^2 (0<a<1,1<a≦3)
2.
(1) P(sin(θ-π/4),sin(θ+π/4),0)
Q(ηsin(θ-π/3),ηsin(θ+π/3),-ηsinθ) (η=2/√6)
M:(1+tanθ)x+(1-tanθ)y+(1-√3)z=0
(2) (1,1,1+√3)
3.
(1) 1-(1/7)^n
(2) (6^n-1)/(5×6^n)
(3) 30(2^(n-1)-1)/(6^n-1)