Question

Sin63`Sin33`+Sin27`Sin57`的值

Answer 1

根据公式:sin(a+b)=sin(a)cos(b)+cos(α)sin(b),

.

将Sin63*Sin33+Sin27*Sin57化简：

sin63*sin33+sin27*sin57

=sin63*cos57`+cos63*sin57

=sin(63+57)

=sin120

=sin60

=(根号3)/2.