Question

Упростите выражение
$2 sin^{2} x+3+2 ctg^{2} x sin^{2} x$

Answer 1

2sin²(x)+3+2ctg²(x)sin²(x) = 2sin²(x)+3+2(cos²(x)/sin²(x))*sin²(x) = 
2sin²(x)+3+2cos²(x) = 2(sin²(x)+cos²(x))+3=2*1+3=5