\cos 2\alpha =\cos^2\alpha -\sin^2\alpha ,\tan 2\alpha =\frac{2\tan \alpha }{1-\tan^2\alpha },同理,我们可以证得如下三倍角公式:\sin 3\alpha =3\sin\alpha -4\sin^3\alpha ,\cos 3\alpha =___(要求用\cos\alpha 来表示),\tan 3\alpha =___(要求用\tan\alpha 来表示)....
sin^2\alpha +cos^2\alpha =___。 相关知识点: 试题来源: 解析 1设直角△ABC中,∠C =90°, ∠A=α ,a的 对边是a,邻边是b,斜边是c. 则有 a^2+b^2=c^2 , sinα=a/c , cosα=b/c , 所以 sin^2α+cos^2α=(a^2+b^2)/(c^2)=(c^2)/(c^2)=1 故答案为1. 反馈 ...
Step by step video & image solution for If p = cos 2alpha + i sin 2alpha , q = cos 2beta + i sin 2beta then the value of sqrt(p/q) - sqrt(q/p)= by Maths experts to help you in doubts & scoring excellent marks in Class 11 exams.Updated on:21/07/2023 ...
Answer Step by step video & image solution for cos(alpha/2)+sin(alpha/2)=sqrt(2)(cos3 6^(@)-sin1 8^(@)) by Maths experts to help you in doubts & scoring excellent marks in Class 11 exams. Updated on:21/07/2023 Doubtnut is No.1 Study App and Learning App with Instant Video...
sin(α)+sin(β)=2sin(2α+β)cos(2α−β) Solve for α α∈C Solve for β β∈C Quiz Complex Number sinα+sinβ=2sin2α+βcos2α−β Similar Problems from Web Search Why is sinα+sinβ=2sin(...
(1)降幂公式:sin^2\alpha =___,cos^2\alpha =___;(2)升幂公式:1+cos\alpha =___,1-cos\alpha
由\sin \alpha =2\cos \alpha ,得\tan \alpha =2, 所以;\sin \alpha \cos \alpha =\frac{1}{2}\sin 2\alpha =\frac{1}{2}\times \frac{2\tan \alpha }{1+{{\tan }^{2}}\alpha }=\frac{1}{2}\times \frac{2\times 2}{1+4}=\frac{2}{5}. 故答案为:\frac{2}{5}.反馈...
Class 12 MATHS If `A=[(cos^(2)alpha, cos alpha sin alph... If A=[cos2αcosαsinαcosαsinαsin2α] and B=[cos2βcosβsinβcosβsinβsin2β] are two matrices such that the product AB is null matrix, then α−β is A 0 B multiple of π C an odd multiple of π/2 ...
পরাবৃত্ত x^2/(cos^2alpha) - y^2/(sin^2alpha) = 1 - এর ক্ষেত্রে alpha পরিবর্তিত হলেও নিম্নলিখিতগুলির কোনট
Rearranging, we havesin2(a)=cos2(b)+cos2(c)Sincea=π−(b+c), we getsin2(b+c)=cos2(b)+cos2(c)Hence,(sin(b)cos(c)+cos(b)sin(c))2=cos2(b)+cos2(c)... Ifα+β−γ=πProve that(sin2α+sin2β−sin2γ)=2sin alpha ...