因此,sin15∘sin75∘=14\sin 15^\circ \sin 75^\circ = \frac{1}{4}sin15∘sin75∘=41。
Answer to: What is sin (15 degrees) times sin (75 degrees) equal to? (In degrees) By signing up, you'll get thousands of step-by-step solutions to...
$\left(2\right)sin (75)^(° )sin (15)^(° )=sin ((90)^(° )-(15)^(° ))sin (15)^(° )=\cos {15}^{\circ }\sin {15}^{\circ }=\dfrac{1}{2}\sin {30}^{\circ }=\dfrac{1}{2}\times \dfrac{1}{2}=\dfrac{1}{4}$.结果...
求下列各式的值: ( 1 )sin15°sin30^(° )sin75°; ( 2 )cos36°cos72°; ( 3 ) ( (tan5°-tan85°) )
参考答案: cos75°cos15°-sin255°sin165°=cos75°cos15°-sin(180°+75°)sin(180°-15°)=cos75°cos15°+sin75°sin15°=cos(75°-15°)=cos60°= 1 2 .故选A 复制 纠错举一反三 T-210罐压达到()mbar安全阀排放至火炬 A. 270mbar B. 280mbar C. 290mbar D. 265mbar 查看...
【解析】 $$解: \sin15^{\circ}\sin 30^{\circ}\sin 75^{\circ} \\ =s^{\circ}m15^{\circ}\sin 30^{\circ}\cos 15^{\circ} \\ = \sin 15^{\circ}\cos 15^{\circ}\sin 30^{\circ} \\ = \frac{1}{2}\sin 30^{\circ}\cdot \sin 30^{\circ} \\ = \frac{1}{2}\times...
$sin{15}^{\circ }sin{75}^{\circ }=sin(15)^(° )sin ( (90^(° )-(15)^(° )) )=sin{15}^{\circ }cos{15}^{\circ }$ $=\dfrac {1} {2}sin3{0}^{\circ }=\dfrac {1} {2}\times \, \dfrac {1} {2}=\dfrac {1} {4}$。 故选:B。结果...
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解析 原式$=sin15°cos15°+sin75°cos75°= 1 2sin30°+ 1 2sin150°=\dfrac {1} {2}\times \dfrac {1} {2}+\dfrac {1} {2}\times \dfrac {1} {2}=\dfrac {1} {2}$ 综上所述,答案为:$\dfrac {1} {2}$反馈 收藏
$=\left | {\overrightarrow{OB}} \right |^{2}-2\times \dfrac {1} {2}+\left | {\overrightarrow{OA}} \right |^{2}$ $=1-1+1$ $=1$ $\therefore \overrightarrow{OB}-\overrightarrow{OA}=\overrightarrow{AB}=1$ 综上所述,答案选:$D$结果...