Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If cot $(x+y)=1 / \sqrt{3}, \cot (x-y)=\sqrt{3}$ then what are the smallest positive values of $x$ and $y$ respectively?
MathematicsTrigonometric Ratios & IdentitiesNDANDA 2009 (Phase 1)
Options:
  • A $45^{\circ}, 30^{\circ}$
  • B $30^{\circ}, 45^{\circ}$
  • C $15^{\circ}, 60^{\circ}$
  • D $45^{\circ}, 15^{\circ}$
Solution:
1350 Upvotes Verified Answer
The correct answer is: $45^{\circ}, 15^{\circ}$
Since $\quad \cot (x+y)=\frac{1}{\sqrt{3}}=\cot 60^{\circ} \quad\left[\cot 60^{\circ}=\frac{1}{\sqrt{3}}\right]$
$\Rightarrow x+y=60^{\circ}$
and $\cot (x-y)=\sqrt{3}=\cot 30^{\circ}$
$\Rightarrow x-y=30^{\circ}$
From equations (i) and (ii), we get $x=45^{\circ}$ and $y=15^{\circ}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.