Mathematics - Application of Derivative Question with Solution | TestHub

MathematicsApplication of DerivativeMaxima-MinimaMedium2 minPYQ_2013
MathematicsMediummatching list

A line L : y = m x + 3 meets y - a x is at E(0,3) and the arc of the parabola y 2 = 1 6 x , 0 y 6 at the point F x 0 y 0 .The tangent to the parabola at F x 0 y 0 intersects the y-axis at G 0 y 1 .The slope m of the line L is chosen such that the area of the triangle EFG has a local maximum.
Match List I with List II and select the correct answer using the code given below the lists :

 List I List II
A.m = P. 1 2
B.Maximum area of ΔEFG isQ.4
C.y0​ =R.2
D.y1 = S.1

Options:

Answer:
B
Solution:

tangent at F      yt = c + 4t2
a : x = 0        y = 4t   (0,4t)
(4t2,8t) satisfies the line
8t = 4mt2+ 3
4mt2- 8t + 3 = 0
Area = 1 2 0 3 1 0 4 t 1 4 t 2 8 t 1

= 1 2 4 t 2 3 - 4 t
= 2 t 2 3 - 4 t
A = 2 3 t 2 - 4 t 3
= dA dt = 2 6 t - 1 2 t 2
= 24 t(1 - 2t)

t = 1/2 maxima
G 0 4 t G 0 2
y1= 2
x 0 y 0 = 4 t 2 8 t = 1 4
y 0 = 4
Area = 2 3 4 - 1 2 = 2 3 - 2 4 = 1 2

Stream:JEE_ADVSubject:MathematicsTopic:Application of DerivativeSubtopic:Maxima-Minima
2mℹ️ Source: PYQ_2013

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