Упростите выражение (sin234°+cos216°/sin144°-cos126°)*2tg36°

Question

Упростите выражение (sin234°+cos216°/sin144°-cos126°)*2tg36°

Answer 1

(sin(270-36)+cos(180+36))/(sin(180-36)-cos(90+36)) *tg36=
=(-cos36-cos36)/(sin36+sin36 *tg36=-2cos36/2sin36 *tg36=ctg36*tg36=1