Question

已知cos(x-pai/6)+sinx=4乘根号3/5,则sin(x+7pai)=

Answer 1

cos(x-π/6)+sinx=4√3/5

cosxcosπ/6+sinxsinπ/6+sinx=4√3/5

(√3/2)cosx+(3/2)sinx=4√3/5

(1/2)cosx+(√3/2)sinx=4/5

sin(π/6+x)=4/5

sin(7π/6+x)=-4/5