【题目】已知α为钝角,$$ \cos ( \alpha - \frac { \pi } { 4 } ) = \frac { \sqrt { 2 } } { 3 } $$,求cosα. 相关知识点: 试题来源: 解析 【解析】 ∵$$ \frac { \pi } { 2 } 结果一 题目 【题目】已知a为镜角,c(-)-,求cos 答案 【解析】 2ana3,又 co(a-),...
( \pi + \alpha ) = \textcircled { 1 1 } \_ \_ \_ $$ 两个角的同一三角函数值的$$ \tan ( \pi + \alpha ) = \textcircled { 1 2 } $$关系$$ \sin ( \frac { \pi } { 2 } - \alpha ) = \textcircled { 1 3 } \_ $$公式五$$ \cos ( \frac { \pi } { 2...
সঠিক উত্তরটি নির্বাচন করো cos15°+sin15°= IfA=[cosαsinα−sinαcosα], show that A^(2)=[{:(cos2alpha,sin2alpha),(-sin2alpha,cos2alpha) :}]. View Solution দুটি পরস্পর পৃথক ...
sin 3 alpha = 4 sin alpha sin(x + alpha) sin(x-alpha) 05:22 The general solution of 4 sin^4 x + cos^4x= 1 is 02:39 For n in Z , the general solution of (sqrt(3)-1)sintheta+(sqrt(3)+1)c... 02:34 The value of cosycos(pi/2-x)-cos(pi/2-y)cosx+sinycos(pi/2...
解析:cosalpha;=-35,alpha;isin;(pi;2,pi;),所以sinalpha;=45,there4;tanalpha;=sinalpha;cosalpha;=-43.相关知识点: 试题来源: 解析 答案:-43 解析:cosalpha;=-35,alpha;isin;(pi;2,pi;),所以sinalpha;=45,there4;tanalpha;=sinalpha;cosalpha;=-43.反馈...
【题目】诱导公式六:$$ \sin ( \frac { \pi } { 2 } + \alpha ) = \cos \alpha , \cos ( \frac { \pi } { 2 } + \alpha ) = - s i $$nα.课本中已经给出了推导方法,你还能用其他的方法推导出这两个公式吗? 相关知识点: ...
因为sin\alpha =0.8,且\alpha \in (0,\pi) 所以cos\alpha =0.6或cos\alpha =-0.6 cos2\alpha =1-2sin^2\alpha =1-2\times 0.64=-0.28 当cos\alpha =0.6时, sin2\alpha =2sin\alpha cos\alpha =2\times 0.8\times 0.6=0.96 当cos\alpha =-0.6时, sin2\alpha =2sin\alpha cos\alpha...
If a is any real number then :(sin^(4)alpha+sin^(2)alpha*cos^(2)alpha+cos^(2)alpha)/(sin^(2)alpha+sin^(2)alpha*cos^(2)alpha+sin^(2)alpha)= View Solution Let alpha=(pi)/(5) and A,=[[cos alpha,sin alpha-sin alpha,cos alpha]] then B=A^(4)-A^(3)+A^(2)-A is...
如何利用该公式推导诱导公式$$ \cos ( \frac { \pi } { 2 } - \alpha ) = \sin \alpha ? $$___ 答案 提示:$$ \cos ( \frac { \pi } { 2 } - \alpha ) = \cos \frac { \pi } { 2 } \cos \alpha + $$ $$ \sin \frac { \pi } { 2 } \sin \alpha = 0...
【解析】通解 依题意得$$ 4 \sin \alpha \cos \alpha = 2 \cos ^ { 2 } \alpha $$,由$$ \alpha \in ( 0 , \frac { \pi } { 2 } ) $$,知 $$ \cos \alpha > 0 $$,所以$$ 2 \sin \alpha = \cos \alpha $$.又$$ \sin ^ { 2 } \alpha + \cos ^ { 2 }...