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JEE Mains · Maths · STD 11 - Trigonometrical equations
The number of solutions of \(sin \,3x\, = cos\, 2x\) , in the interval \(\left( {\frac{\pi }{2},\pi } \right)\) is
- A \(3\)
- B \(4\)
- C \(2\)
- D \(1\)
Answer & Solution
Correct Answer
(D) \(1\)
Step-by-step Solution
Detailed explanation
Given \(\sin \,3x\, = \,\cos 2x\) \( \Rightarrow {\kern 1pt} \sin \,3x\, = \,\sin \,(\pi /2 - 2x)\) We now that \(\sin A = \sin B\) \( \Rightarrow \,A\, = \,n\pi + {( - )^n}B,\) where \(n\) is an integer Using the above identity , we get…
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