Question

Упростить 1)sin^4 x-cos^4 x/sin2x
2)sin18*cos27+sin108*sin27

Answer 1

1
(sin²x-cos²x)(sin²x+cos²x)/sin2x=-cos2x/sin2x=-ctg2x
2
sin18cos27+sin(90+18)sin27=sin18cos27+cos18sin27=sin*18+27)=sin45=
=√2/2