Saved Bookmarks
| 1. |
Find the curves for which the length of normal is equal to the radius vector.A. circlesB. rectangular hyperbolaC. ellipsesD. straight lines |
|
Answer» Correct Answer - A::B We have length of the normal = radius vector or `ysqrt(1+((dy)/(dx))^(2)) = sqrt((x^(2)+y^(2))` or `y^(2)(1+((dy)/(dx))^(2)) = x^(2)+y^(2)` or `x=+-y(dy)/(dx)` i.e., `x=y(dy)/(dx)` or `x=-y(dy)/(dx)` i.e., `x=y(dy)/(dx)` or `x=-y(dy)/(dx)` i.e., `xdx-ydy=0` or `xdx+ydy=0` Clearly, `x^(2)-y^(2)=c_(1)` represents a rectangular hyperbola and `x^(2)+y^(2)=c_(2)` represents circles. |
|