

InterviewSolution
Saved Bookmarks
1. |
`y = cos ^(-1)((1 - x^(2))/(1+ x^(2))) 0 lt x lt 1` |
Answer» `y = cos ^(-1)((1 - x^(2))/(1+ x^(2)))` Let `x tan theta` ltbgt `rArr theta = tan^(-1) x ` `rArr y = cos^(-1)((1 - tan^(2)theta)/(1 +tan^(2)theta))` `=cos^(-1)((cos^(2)theta-sin^(2)theta)/(cos^(2)theta + sin^(2) theta))` `= cos ^(-1)(cos2theta)= 2theta= 2tan^(-1)x` `rArr (dy)/(dx) = 2 (d)/(dx) tan^(-1)x = (2)/(1+ x^(2))`. |
|