Question

f(x)=sin(x-6分之派)、已知a、b属于（0、2分之派）、且f（a）=五分之三、f（b）=十三分之十二、那么f（

Answer 1

f(a)=sin(a-π/6)=3/5

f(b)=sin(b-π/6)=12/13

cos(a-π/6)=4/5

cos(b-π/6)=5/13

sin(a-b)=sin[(a-π/6)-(b-π/6)]

= -33/65

cos(a-b)=56/65

f(a-b)=sin(a-b)cosπ/6-cos(a-b)sinπ/6

=-(33√3+56)/130