Saved Bookmarks
| 1. |
The value of cos² x + cos² y – 2cos x × cos y × cos (x + y) is |
Answer» Cos²x+cos²y-2cosx.cosy.COS(x+y)cos²x+1-sin²y-2cosx.cosy.cos(x+y)1+cos²x-sin²y-2cosx.cosy.cos(x+y)1+cos(x+y).cos(x-y)-2cosx.cosy.cos(x+y)1+cos(x+y){ cos(x-y)-2cosx.cosy }1+cos(x+y){ cosx.cosy-sinx.siny-2cosx.cosy }1+cos(x+y){ -cosx.cosy + sinx.siny }1-cos(x+y){ cosx.cosy-sinxsiny }1-cos(x+y).cos(x+y)1-cos²(x+y)sin²(x+y). |
|