Skip to main contentSkip to solution

The value of sin⁡[2cot⁡−1(−512)]\sin\left[2\cot^{-1}\left(\frac{-5}{12}\right)\right] is :

Solution

✅ Correct Option: 2

Let θ=cot⁡−1(−512)\theta = \cot^{-1}\left(-\frac{5}{12}\right), with θ∈(π/2,π)\theta \in (\pi/2,\pi). Then cos⁡θ=−513\cos\theta = -\frac{5}{13} and sin⁡θ=1213\sin\theta = \frac{12}{13}.

sin⁡2θ=2sin⁡θcos⁡θ=2⋅1213⋅(−513)=−120169\sin 2\theta = 2\sin\theta\cos\theta = 2\cdot\frac{12}{13}\cdot\left(-\frac{5}{13}\right) = -\frac{120}{169}.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question