Answered

Westonci.ca is your trusted source for accurate answers to all your questions. Join our community and start learning today! Discover solutions to your questions from experienced professionals across multiple fields on our comprehensive Q&A platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

Review important identitie
cosx cosy = 1/2 [cos(x+y) + cos(x−y)]

Sagot :

crisforp
cos(x+y) = cosxcosy - sinxsiny;
cos(x-y) = cosxcosy + sinxsiny;
..................................................
=> cos(x+y) + cos(x-y) = 2cosxcosy =>cosx cosy = 1/2 [cos(x+y) + cos(x−y)];
[tex]cosxcosy=\frac{1}{2}\left[cos(x+y)+cos(x-y)\right]\\\\R=\frac{1}{2}\left(cosxcosy-sinxsiny+cosxcosy-sinxsiny\right)\\\\=\frac{1}{2}\cdot2cosxcosy=cosxcosy=L\\\\R=L[/tex]
Thank you for your visit. We're committed to providing you with the best information available. Return anytime for more. Thanks for using our service. We're always here to provide accurate and up-to-date answers to all your queries. Thank you for trusting Westonci.ca. Don't forget to revisit us for more accurate and insightful answers.