以下将a作为α,b作为β
cos(a+b)=sin(a-b)
=>cosacosb-sinasinb=sinacosb-sinbcosa
=>cosa(cosb+sinb)=sina(cosb+sinb)
=>(cosa-sina)(cosb+sinb)=0
∵0
以下将a作为α,b作为β
cos(a+b)=sin(a-b)
=>cosacosb-sinasinb=sinacosb-sinbcosa
=>cosa(cosb+sinb)=sina(cosb+sinb)
=>(cosa-sina)(cosb+sinb)=0
∵0