1) (1+cosa)(1-cosa) = 1-cos^2a= sin^2a
2)sin^2a * ctg^2a= sin^2a * cos^2a/sin^2a= cos^2a
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
1) (1+cosa)(1-cosa) = 1-cos^2a= sin^2a
2)sin^2a * ctg^2a= sin^2a * cos^2a/sin^2a= cos^2a