Question

已知sin(x+派/6)＝1/4，求sin(x-5/6派)＋sin(派/3－x)值。。速度。。

Answer 1

sin(x-5π/6)=sin[(x+π/6)-π]= -sin(x+π/6)= - 1/4
sin(π/3-x)=sin(π/2-(x+π/6))=cos(x+π/6)=±根号下（15）/4
sin(x-5π/6)+sin(π/3-x)= -1/4±根号下（15）/4

Answer 2

sin(x-5/6派)＋sin(派/3－x)
=sin[(x+π/6)-π]+sin[(π/2)-(π/6+x)]
=-sin(x+π/6)+cos(π/6+x)
=-1/4±√15/4

Answer 3

sin(x-5π/6)＋sin(π/3－x)
=sin[(x-5π/6)+π]+cos[π/2-(π/3-x)]
=-sin(x+π/6)+cos(x+π/6)
因为x+π/6的值未知所以cos(x+π/6)可正可负
所以原式等于-1/4±√15/4