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AP EAMCET · Maths · Straight Lines

In a triangle \(\mathrm{ABC},(\mathrm{b}+\mathrm{c}) \sin \frac{A}{2}=\)

  1. A \(a \cos A\)
  2. B \(a \cos \left(\frac{B-C}{2}\right)\)
  3. C \(a \sin \left(\frac{B+C}{2}\right)\)
  4. D \(a \sin \left(\frac{B-C}{2}\right)\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(a \cos \left(\frac{B-C}{2}\right)\)

Step-by-step Solution

Detailed explanation

In \(\varnothing \mathrm{ABC}(\mathrm{b}+\mathrm{c}) \operatorname{Sin}\left(\frac{\mathrm{A}}{2}\right)=\) ? By \(\operatorname{Sin}\) rule \(\frac{a}{\operatorname{Sin} A}=\frac{b}{\operatorname{Sin} A}=\frac{c}{\operatorname{Sin} C}=k\)…