Question

Представьте в виде произведения:

Answer 1

cos(π/4+a)-cos(π/4-a)=-2sin[(π/4+a-π/4+a)/2]*sin[(π/4+a+π/4-a)/2]=
=-2sina*sinπ/4=-2*√2/2*sina=-√2sina

Answer 2

=-2sin( π/4+a-π/4+a/2 ) *sin ( π/4+a+π/4-a/2 ) = -2sina * sin π/4 = -2sina*√2/2=
=-sina* √2