A point is moving on$y = 4 - 2x^{2}$. The $x -$coordinate of the point is decreasing at the rate of 5 unit per second. Then, the rate at which y-coordinate of the point is changing when the point is at (1,2)is

Question

Dr. Abubacker · Accepted Answer

(d)
Given equation of curve is
$\ \ y = 4 - 2x^{2}$
$\Rightarrow \ \ \frac{dy}{dt} = - 4x\frac{dx}{dt}$
$Given\ \ \ \ \ \frac{dx}{dt} = - 5,\ at\ point\ (1,2)$
$	herefore\frac{dy}{dt} = - 4(1)( - 5) = 20unit/s$

Q. A point is moving on$y = 4 - 2x^{2}$. The $x -$coordinate of the point is decreasing at the rate of 5 unit per second. Then, the rate at which y-coordinate of the point is changing when the point is at (1,2)is

Explanation

Reviewed by Dr. Abubacker

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