Mark the correct alternative in the following:
The coordinates of the point on the ellipse 16x2+9y2=400 where the ordinate decreases at the same rate at which the abscissa increase, are:
Taking ellipse to be 16x2+9y2=400 instead of 46x2+9y2=400
Let E(x,y):16x2+9y2=400
Solving for y, we get
- (1)
Given that , we have to calculate x,y
Differentiating (1) with respect to t, we get
Substituting values, we get
Simplifying the equation, we get
Squaring both sides
256x2=9(400-16x2)
Solving the equation, we get
x2=9
x=±3
Substituting in (1), we get
By seeing the graph of E(x,y), we can conclude that the point has to lie in Ist or IIIrd quadrant, as only in these quadrants, the increase in abscissa leads to decrease in ordinate.
Hence the points are