Ex 7.3, 3 - Integrate cos 2x cos 4x cos 6x - Ex 7.3

Slide6.JPG
Slide7.JPG Slide8.JPG

  1. Chapter 7 Class 12 Integrals
  2. Serial order wise
Ask Download

Transcript

Ex 7.3, 3 cos 2x cos 4x cos 6x We know that 2 cos A cos B= cos + + cos Replace A by 2 & B by 4 2 cos 2 cos 4 = cos 2 +4 + cos 2 4 2 cos 2 cos 4 = cos 6 + cos 2 2 cos 2 cos 4 = cos 6 + cos 2 cos 2 cos 4 = 1 2 cos 6 + cos 2 cos 2 cos 4 cos 6 = 1 2 cos 6 + cos 2 cos 6 = 1 2 cos 6 + cos 2 cos 6 = 1 2 cos 6 2 + cos 2 . cos 6 = 1 2 cos 6 2 + cos 2 . cos 6 Now, cos 2 cos 4 cos 6 = 1 2 cos 2 6 + 2 cos 6 = 1 2 1 2 12 +1 + 1 2 8 + cos 4 = 1 4 12 +1 + ( 8 + cos 4 ) = 1 4 12 + 1 + cos 8 + cos 4 = + + + +

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.