【题目】诱导公式$$ \sin ( \alpha + 2 k \pi ) = \textcircled { 1 } $$揭示了终边相同的两个角的公式$$ \cos (
【解析】 知识点2(1) $$ \frac { 1 + \cos 2 \alpha } { 2 } $$ $$ \frac { 1 - \cos 2 \alpha } { 2 } $$ (2)2$$ \cos ^ { 2 } $$若a 2$$ 2 \sin ^ { 2 } $$a(3)$$ \tan ( \alpha \pm \beta ) ( 1 $$ tanatan3)$$ \frac { \tan \alpha ...
α=πn2+2π, n2∈Z 解α α=22πn1+arcsin(54), n1∈Z α=πn2+2π, n2∈Z 測驗 Trigonometry 2sin2α=cos2α+1 來自Web 搜索的類似問題 If sinα+cosα=0.2, find the numerical value of sin2α. https://math.stackexchange.com/questions/451199/if-sin-alpha-cos-alpha-0-2-find-the...
sin^(3)xsin(x+alpha)=sin^(3)x(sinx cos alpha + cosx sin alpha) =sin^(4)x(cos alpha+cotx sin alpha) I=int(1)/(sqrt(sin^(3)xsin(x+alpha)))dx =int(1)/(sin^(2)xsqrt(cos alpha +cotxsin alpha))dx =int("cosec"^(2)x)/(sqrt(cos alpha+cotx sin alpha))dx
Ifα+β−γ=πProve that(sin2α+sin2β−sin2γ)=2sin alpha ×2sin beta ×2 cos gamma#? https://socratic.org/questions/if-alpha-beta-gamma-pi-prove-that-sin-2alpha-sin-2beta-sin-2gamma-2sin-alpha-2si P dilip_k Jul 9, 2018LHS=si...
【解析】 (1)由倍角公式得$$ \sin 2 \alpha = 2 \sin \alpha \cos \alpha $$ 综上所述,答案:2sinacosα (2)由倍角公式得$$ \cos 2 \alpha = \cos ^ { 2 } \alpha - \sin ^ { 2 } \alpha $$ $$ = 2 c o s ^ { 2 } \alpha - 1 = 1 - 2 s i n ^ { 2 } \...
知识点一 二倍角的正弦公式及变形$$ S _ { 2 \alpha } : \sin 2 \alpha = \boxed { 1 } , \sin \alpha \co
【题目】2. 二倍角的正弦、余弦和正切公式$$ 1 ) \sin 2 \alpha = \_ . $$(2)cos 2α=___=___=___.(3)tan 2α=___$$ ( \alpha \neq \frac { k \pi } { 2 } + \frac { \pi } { 4 } $$且$$ \alpha \neq k \pi + \frac { \pi } { 2 } , k...
1.解析:∵$$ \tan \alpha = - 2 $$,∴α是第二、四象限角, 又由$$ \tan \alpha = - 2 $$得$$ \sin \alpha = - 2 \cos \alpha . $$ (1)当α为第二象限角时,$$\left\{ \begin{matrix} \sin \alpha = - 2 \cos \alpha , \\ \Rightarrow 5 \cos ^ { 2 } \alpha = ...
9. 解:(1)由已知得$$ 2 \sin \alpha = - \cos \alpha $$,所以$$ \tan \alpha = - \frac { 1 } { 2 } $$, 则$$ \sin \alpha \cos \alpha + \cos 2 \alpha = \frac { \sin \alpha \cos \alpha + \cos ^ { 2 } \alpha - \sin ^ { 2 } \alpha } { \si...