Question

Проверьте равенства пожалуйста

Answer 1

$\frac{cos64sin86+cos86sin64}{cos71sin49+cos49sin71} = \frac{sin150}{sin120} \neq 1$

$\frac{sin26cos6+sin6cos24}{cos65sin85+cos85sin65} = \frac{sin30}{sin150}= \frac{sin30}{sin30}= 1$

Answer 2

1)(cos64cos4+sin4sin64)/(cos71cos41+sin41sin71)=cos(64-4)/cos(71-41)=
=cos60/cos30=1/2:√3/2=1/2*2/√3=1/√3
1/√3≠1
2)(cos66cos6+sin6sin66)/(cos65cos5+sin5sin65)=cos(66-6)/cos(65-5)=
=cos60/cos60=1
1=1