Mathematics · 2026
JEE Main · 22 January 2026, Shift 2 · Q23
Let cos (α+β)=-1/10 and sin (α-β)=3/8, where 0<α<(π)/3 and 0<β<(π)/4. If tan 2 α=(3(1-r √ 5 ))/(√ 11 (s+√ 5 )), r, s ∈ N, then r+s is equal to ____.
Let $\displaystyle \cos (\alpha+\beta)=-\frac{1}{10}$ and $\displaystyle \sin (\alpha-\beta)=\frac{3}{8}$, where $\displaystyle 0<\alpha<\frac{\pi}{3}$ and $\displaystyle 0<\beta<\frac{\pi}{4}$.
If $\displaystyle \tan 2 \alpha=\frac{3(1-r \sqrt{5})}{\sqrt{11}(s+\sqrt{5})}, r, s \in \mathbf{N}$, then $\displaystyle r+s$ is equal to $\displaystyle \_\_\_\_$.
Official answer
From NTA’s final answer key for this paper.
20
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JEE Main 2026 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.