送交者: xinlihuaxys 于 2008-12-12, 15:54:57:
回答: 那有什么不可以的。 由 xinlihuaxys 于 2008-12-12, 14:40:27:
If t + t' = 180° then:
sin(t) = sin(t')
cos(t) = -cos(t')
tan(t) = -tan(t')
cot(t) = -cot(t')
If t + t' = 90° then:
sin(t) = cos(t')
cos(t) = sin(t')
tan(t) = cot(t')
cot(t) = tan(t')
cos(u-v) = cos(u).cos(v) + sin(u).sin(v)
cos(u + v) = cos(u - (-v)) = cos(u).cos(-v) + sin(u).sin(-v)
sin(u - v) = sin(u).cos(v) - cos(u).sin(v)
sin(u + v) = sin(u).cos(v) + cos(u).sin(v)
tan(u + v) = sin(u + v)
cos(u + v)
= sin(u).cos(v) + cos(u).sin(v)
cos(u).cos(v) - sin(u).sin(v)
tan(u + v) = tan(u) + tan(v)
1 - tan(u).tan(v)
sin(2u) = 2sin(u).cos(u)
cos(2u) = cos2(u) - sin2(u)
tan(2u) = 2tan(u)
1- tan2(u)
cos(2u) = 1 - tan2(u)
1 + tan2(u)
sin(2u) = 2tan(u)
1 + tan2(u)
1 + cos(2u) = 2 cos2(u)
1 - cos(2u) = 2 sin2(u)