{1 - \tan \alpha \ast \tan \beta }③利用这些公式可将某些不是特殊角的三角函数转化为特殊角的三角函数来求值,如:\tan 105^{{\circ} }=\tan (45^{{\circ} }+ 60^{{\circ} }) = \dfrac{\tan 45^{{\circ} } + \tan 60^{{\circ} }}{1 - \tan 45^{{\circ} }\ast \tan 60...
{1 + \tan \alpha \tan \beta }(1+ \tan \alpha \tan \beta \neq 0)利用这些公式可以将一些不是特殊角的三角函数转化为特殊角的三角函数来求值.如:\tan 105^{{\circ} }= \tan (45^{{\circ} }+ 60^{{\circ} })= \dfrac{\tan 45^{{\circ} } + \tan 60^{{\circ} }}{1 - \ta...
【解析】 根据两角和的正弦、余弦和正切公式有: (1)$$ \sin ( \alpha + \beta ) = \sin \alpha \cos \beta + \cos \alpha \sin $$ (2)$$ \cos ( \alpha + \beta ) = \cos \alpha \cos \beta - \beta \sin \alpha \sin $$ (3) nβ $$ \tan ( \alpha + \beta ) = \fr...
【题目】一、和角的正弦、余弦、正切公式:(1)$$ \sin ( \alpha + \beta ) = $$(2)$$ \sin ( \alpha - \beta ) = \_ $$(3)$$ ) \cos ( \alpha + \beta ) = $$(4)$$ \cos ( \alpha - \beta ) = \_ $$(5)$$ ) \tan ( \alpha + \beta ) = \_ $$(6)$$ ) \...
1.提示:①$$ \sin ( \alpha + \beta ) = \cos \left[ \frac { \pi } { 2 } - ( \alpha + \beta ) \right] = $$ $$ \cos \left[ ( \frac { \pi } { 2 } - \alpha ) - \beta \right] = \cos ( \frac { \pi } { 2 } - \alpha ) \cos \beta \\ + \sin...
alpha \sin \beta $$,其$$ \beta \in R $$,简记作$$ S _ { ( \alpha + \beta ) } $$;(3)两角差的正弦公式$$ i n ( \alpha - \beta ) = \sin \alpha \cos \beta - \cos \alpha \sin \beta , $$,其中α,$$ \beta \in R $$,简记作 $$ S _ { ( \alpha - \beta )...
一、和角的正弦、余弦、正切公式: (1)$$ \sin ( \alpha + \beta ) = \sin \alpha \cos \beta + \cos \alpha \sin \beta $$ (2)$$ \sin ( \alpha - \beta ) = \sin \alpha \cos \beta - \cos a \sin $$ ; (3)$$ \cos ( \alpha + \beta ) = \cos \alpha \cos \beta ...
{ \tan \alpha - \tan \beta } { 1 + \tan \alpha \tan \beta } $$ $$ \alpha - \beta \neq k \pi + \frac { \pi } { 2 } ) ( k \in Z ) $$ 故答案为: (1))sinacosβ-cosasinβ (2)$$ \cos \alpha s o s \beta + \sin \alpha \sin \beta $$ (3)$$ \frac ...
1.两角和与差的正弦、余弦、正切公式(1)$$ S _ { ( \alpha + \beta ) } : \sin ( \alpha + \beta ) = \sin \alpha \cos \beta + \cos \alpha \sin \beta $$(2)$$ S _ { ( \alpha - \beta ) } : \sin ( \alpha - \beta ) = \underline { \sin \alpha \cos \...
【题目】一、两角和与差的正弦、余弦、正切公式$$ \sin ( \alpha + \beta ) = \_ \sin ( \alpha - \beta ) = \_ ; $$$ \cos ( \alpha + \beta ) = \_ \cos ( \alpha - \beta ) = \_ ; $$$ \tan ( \alpha + \beta ) = \_ ; \tan ( \alpha - \beta ) = \_ . $...