© examsiri.com
Question : 25 of 160
Marks:
+1,
-0
Solution:
Given equation is
‌1+cos‌x+cos2x+...+∞=4+2√3⇒‌=4+2√3⇒1−cos‌x=‌×‌⇒1−cos‌x=‌⇒1−cos‌x=1−‌⇒cos‌x=‌=cos‌⇒x=2nπ±‌⇒x=‌⇒x=(12n±1)‌
© examsiri.com
Go to Question: