\displaystyle \overrightarrow{OH}=\overrightarrow{OG}+\overrightarrow{GH}=\left| \overrightarrow{OQ} \right|cost \cdot \overrightarrow{i}+\left| \overrightarrow{QP} \right|sinu \cdot\overrightarrow{i} \displaystyle \overrightarrow{HP}=\overrightarrow{GQ}-\overrightarrow{CQ}=\left| ...
因为角\theta 的终边过点(1,-2), 所以\sin\theta ={-2\over \sqrt{1+(-2)^2} } =-{2\sqrt{5}\over 5 } ,\cos\theta ={1\over \sqrt{1+(-2)^2} } ={\sqrt{5}\over 5 } , 则\sin\theta \cos\theta =-{2\sqrt{5}\over 5 } \times {\sqrt{5}\over 5 }=-{2\over 5}...
Answer to: Establish the identity. csc theta + cot theta = sin theta over 1 - cos theta By signing up, you'll get thousands of step-by-step...
4.复数乘法的几何意义(1)条件:$$ : z _ { 1 } = r _ { 1 } ( \cos \theta _ { 1 } + i \sin \theta _
{n}=(c,d)则\overrightarrow{m}\cdot \overrightarrow{n}=|\overrightarrow{m}|\cdot |\overrightarrow{n}|\cos\langle\overrightarrow{m},\overrightarrow{n}\rangle\leqslant |\overrightarrow{m}|\cdot |\overrightarrow{n}|，代入坐标整理即证，当且仅当\overrightarrow{m}与\overrightarrow{n...
Simplify. 1 + tan^2 theta over 1 + cot^2 theta Simplify the expression. (1 + cot theta) (1 - cot theta) - csc^2 theta A) 2 cot^2 theta. B) 0. C) -2 cot^2 theta. D) 2. Write sec theta (tan theta + cot theta) in terms of...
相关知识点: 试题来源: 解析 (i)2(1-sin²\theta )=3sinθ(2sin(θ-1)(sin(θ+2)=0))θ=30°or150°(ii)n={{their30}\over{10}} =3(their3)θ=720+their150=870θ=290° 反馈 收藏
Answer to: Simplify 9 sin theta (csc theta-sin theta) By signing up, you'll get thousands of step-by-step solutions to your homework questions. You...
即-2\sqrt{5} \sin(\theta -\varphi )\leqslant 3-5a^2(\varphi =\arcsin{1\over \sqrt{5} } )。 又因为对任意实数\theta 成立, 所以2\sqrt{5}|a|\leqslant 3-5a^2 , 解得||a|\leqslant {\sqrt{5} \over 5} 故a的取值范围为[-{\sqrt{5} \over 5} ,{\sqrt{5} \over 5...
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