来自陈五一的问题
【f(cosx)=sinxcosx-根号3/2cos2x,则f(sinπ/12)=】
f(cosx)=sinxcosx-根号3/2cos2x,则f(sinπ/12)=
1回答
2020-07-23 08:31
【f(cosx)=sinxcosx-根号3/2cos2x,则f(sinπ/12)=】
f(cosx)=sinxcosx-根号3/2cos2x,则f(sinπ/12)=
f(cosx)=(1/2)sin2x-(√3/2)cos2x=sin(2x﹣π/3)
f[sin(π/12)]=f[cos(5π/12)]=sin[2(5π/12)-π/3]=sin(π/2)=1