ত্রিকোণমিতিক অনুপাত
(secθ−1secθ+1 \sqrt{\left ( \frac{\sec{θ} - 1}{\sec{θ} + 1} \right.} (secθ+1secθ−1 এর মান কত ?
secθ+cosecθ
cosecθ-cotθ
cosecθ+cotθ
cotθ-cosecθ
secθ−1secθ+1=(secθ−1)(secθ−1)(secθ+1)(secθ−1)=(secθ−1)2sec2θ−1=secθ−1tanθ=secθtanθ−1tanθ \begin{array}{l} \sqrt{\frac{\sec \theta-1}{\sec \theta+1}}=\sqrt{\frac{(\sec \theta-1)(\sec \theta-1)}{(\sec \theta+1)(\sec \theta-1)}} \\ =\sqrt{\frac{(\sec \theta-1)^{2}}{\sec ^{2} \theta-1}}=\frac{\sec \theta-1}{\tan \theta}=\frac{\sec \theta}{\tan \theta}-\frac{1}{\tan \theta}\end{array} secθ+1secθ−1=(secθ+1)(secθ−1)(secθ−1)(secθ−1)=sec2θ−1(secθ−1)2=tanθsecθ−1=tanθsecθ−tanθ1
=(1cosθ)(sinθcosθ)−cotθ=1sinθ−cotθ=cosecθ−cotθ =\frac{\left(\frac{1}{\cos \theta}\right)}{\left(\frac{\sin \theta}{\cos \theta}\right)}-\cot \theta=\frac{1}{\sin \theta}-\cot \theta=\operatorname{cosec} \theta-\cot \theta =(cosθsinθ)(cosθ1)−cotθ=sinθ1−cotθ=cosecθ−cotθ
sinB = 32 \frac{\sqrt{3}}{2} 23 এবং cosC = 12 \frac{1}{2} 21 হলে-
cosB= 12 \frac{1}{2} 21
sinC= 32 \frac{\sqrt{3}}{2} 23
tanB.(sec2C−1)=3 \tan{B} . \sqrt{\left ( \sec^{2}{C}{- 1} \right )} = 3 tanB.(sec2C−1)=3
নিচের কোনটি সঠিক ?
একটি চাকা 114m পথ যেতে 5 বার ঘুরে।
চাকার ব্যাসার্ধ কত ?
cos2θ \cos 2 \theta cos2θ এর মান-
i. 1−2sin2θ 1-2 \sin ^{2} \theta 1−2sin2θ
ii. 1+tan2θsec2θ \frac{1+\tan ^{2} \theta}{\sec ^{2} \theta} sec2θ1+tan2θ
iii. 1−tan2θsec2θ \frac{1-\tan ^{2} \theta}{\sec ^{2} \theta} sec2θ1−tan2θ
নিচের কোনটি সঠিক?
π/2<θ<πএবং sinθ = 5/13 হলে-
