22/09/25 20:52:04.04 Kob8sbcV.net
>>837
>>m1t≡a2-a1 modm2
>>(m1, m2)=Gとすると
>>π^2√3-2∫[t=0→1/2]π｛√1-(1/2-t)^2-√3/2｝^2｝dt
>>1/2-t=cosθとおくと、
>>-dt=-sinθdθ
>>dt=sinθdθ
>>π^2√3-2π∫[θ=π/3→π/2]sinθsinθdθ
>>=π^2√3-2π∫[θ=π/3→π/2]sinθ^2dθ
>>=π^2√3-2π∫[θ=π/3→π/2](1/2-cos2θ/2)dθ
>>=π^2√3-2π[θ=π/3→π/2][θ/2]-2π[θ=π/3→π/2][sin2θ/4]
>>=π^2√3-π^2/6-π√3/4
>>=14.0893726833……