JEE Main 202624 Jan, Morning shiftMathematicsEasyTrigonometry118× since 2002If cotx=512\cot x = \frac{5}{12}cotx=125 for some x∈(π,3π2)x \in \left(\pi, \frac{3\pi}{2}\right)x∈(π,23π), then sin7x(cos13x2+sin13x2)+cos7x(cos13x2−sin13x2)\sin 7x\left(\cos\frac{13x}{2} + \sin\frac{13x}{2}\right) + \cos 7x\left(\cos\frac{13x}{2} - \sin\frac{13x}{2}\right)sin7x(cos213x+sin213x)+cos7x(cos213x−sin213x) is equal toAOption A. 113\frac{1}{\sqrt{13}}131BOption B. 513\frac{5}{\sqrt{13}}135COption C. 626\frac{6}{\sqrt{26}}266DOption D. 426\frac{4}{\sqrt{26}}264CheckSkip · show solution
