2.sinasina/2+sinacosa二分之更号3 =1/2-cos2a/4+更号3/4sin2a = 1/2 +1/2sin(2a-π/6) 最大值=1
1..=sinacosbcosb+cosasinbcosb-1/2sina=== 1/2sina(1+cosbcosb)+1/2cosasin2b-1/2sina= 1/2(sinacos2b+cosasin2b)
嗯
2.sinasina/2+sinacosa二分之更号3 =1/2-cos2a/4+更号3/4sin2a = 1/2 +1/2sin(2a-π/6) 最大值=1
1..=sinacosbcosb+cosasinbcosb-1/2sina=== 1/2sina(1+cosbcosb)+1/2cosasin2b-1/2sina= 1/2(sinacos2b+cosasin2b)
嗯