Applications Of Derivatives Question 107

Question: The line $ x+y=2 $ is tangent to the curve $ x^{2}=3-2y $ at its point

[MP PET 1998]

Options:

A) (1, 1)

B) (-1, 1)

C) ( $ \sqrt{3} $ , 0)

D) (3, -3)

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Answer:

Correct Answer: A

Solution:

Given curve $ x^{2}=3-2y $ …(i)'

Differentiate w.r.t. x, $ 2x=0-2\frac{dy}{dx} $

$ \Rightarrow $ $ \frac{dy}{dx}=-x $

Slope of the tangent of the curve $ =-x $ From the given line, slope $ =-1 $ ,

$ \therefore x=1 $ and from equation (i), $ y=1 $ .

$ \therefore $ Co-ordinate of the point is (1, 1).