InterviewSolution
Saved Bookmarks
| 1. |
If `tanalpha=1/7,sinbeta=1/(sqrt(10)),`prove that`alpha+2beta=pi/4`, where `0 |
|
Answer» `sin beta = 1/sqrt10` `:. cos beta = sqrt(1-(1/sqrt10)^2) = 3/sqrt10` `:. tanbeta = sinbeta/cosbeta = 1/3` Now, `tan2beta = (2tanbeta)/(1-tan^2beta) = (2/3)/(1-1/9) = 6/8 = 3/4` Now, `tan(alpha+2beta) = (tanalpha+tan2beta)/(1-tanalphatan2beta)` `=(1/7+3/4)/(1-1/7(3/4)) = (25/28)/(25/28) = 1` `:. tan(alpha+2beta) = tan (pi/4)` `:. alpha+2beta = pi/4.` |
|