InterviewSolution
Saved Bookmarks
| 1. |
Show that `2(sin^6x+cos^6x)-3(sin^4x+cos^4x)+1=0`. |
|
Answer» `2(sin^6x+cos^6x)-3(sin^4x+cos^4x)+1` `=2[(sin^2x)^3+(cos^2x)^(3)]-3(sin^4x+cos^4x)+1` `=2[(sin^2x+cos^2x)^3-3sin^2xcos^2x(sin^2x+cos^2x)]-3[(sin^2x+cos^2x)^2-2sin^2xcos^2x]+1` `=2[1-3sin^2xcos^2x]-3[1-2sin^2xcos^2x]+1=0` |
|