Saved Bookmarks
| 1. |
Prove that tan72=tan18+2tan54 |
|
Answer» SOLUTION:- LET, tan54 = TAN(72-18) = tan54 =( tan72-tan18)/1+tan72.tan18 = tan54 = ( tan72-tan18)/1+tan(90-18).tan18 = tan54 =( tan72-tan18)/1+cot18.tan18 = tan54 =( tan72-tan18)/2 = tan72-tan18 = 2tan54 =(tan72 = tan18+2tan54)PROVED |
|