JEE Mains · Maths · STD 11 - Trigonometrical equations
If \(2\,cos\,\theta + sin\, \theta \, = 1\) \(\left( {\theta \ne \frac{\pi }{2}} \right)\) , then \(7\, cos\,\theta + 6\, sin\, \theta \) is equal to
- A \(\frac{1}{2}\)
- B \(\frac{46}{5}\)
- C \(\frac{11}{2}\)
- D \(2\)
Answer & Solution
Correct Answer
(D) \(2\)
Step-by-step Solution
Detailed explanation
Given \(2 \cos \theta+\sin \theta=1\) Squaring both sides, we get \((2 \cos \theta+\sin \theta)^{2}=1^{2}\) \(\Rightarrow 4 \cos ^{2} \theta+\sin ^{2} \theta+4 \sin \theta \cos \theta=1\)…
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