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← JEE Main 2026 · 8 Apr · Shift 2
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JEE Main 2026 · 8 Apr · Shift 2, Mathematics question 12

Let α=3sin⁡−1(611)\alpha=3\sin^{-1}\left(\dfrac6{11}\right) and β=3cos⁡−1(49)\beta=3\cos^{-1}\left(\dfrac49\right), where inverse trigonometric functions take only the principal values.

Given below are two statements :

Statement I : cos⁡(α+β)>0\cos(\alpha+\beta)>0.

Statement II : cos⁡(α)<0\cos(\alpha)<0.

In the light of the above statements, choose the correct answer from the options given below :

Choose one option
Answer and worked solution

Official answer: A

Angles.

  • sin⁡−1611≈33.1∘\sin^{-1}\tfrac6{11}\approx33.1^\circ, so α≈99.2∘\alpha\approx99.2^\circ and cos⁡α<0\cos\alpha<0: II is true.
  • cos⁡−149≈63.6∘\cos^{-1}\tfrac49\approx63.6^\circ, so β≈190.8∘\beta\approx190.8^\circ.

Sum. α+β≈290∘\alpha+\beta\approx290^\circ, in the fourth quadrant, so cos⁡(α+β)>0\cos(\alpha+\beta)>0: I is true.

(A)