Maharashtra BoardEnglish MediumSTD 11 ScienceMathsTrigonometric Equations4 Marks
Question
Find the general solutions of the following equations:
$\cos4\text{x}=\cos2\text{x}$
✓
Answer
We have,
$\cos4\text{x}=\cos2\text{x}$
$\Rightarrow\cos4\text{x}=\cos2\text{x}=0$
$\Rightarrow2\sin\text{x}.\sin3\text{x}=0$
$\Rightarrow\text{Either}$
$\sin\text{x}=0$ or $\sin3\text{x}=0$
$\Rightarrow\text{x}=\text{n}\pi,\text{n}\in\text{z}$ or $3\text{x}=\text{m}\pi,\text{m}\in$
Thus,
$\text{x}=\text{n}\pi$ or $\text{m}\frac{\pi}{3},\text{n,m}\in\text{z}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.