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capricornabhi (0)

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Dear Sir/madam,
 
Please help me in the following question:
 
What value of A & B maximizes and minimizes the value of
 
[ a][b ] (X4 -2X 2)dx.
 
 
Thanx
 
Abhi
 
    
rishikesh_anshu (220)

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Simply plot the graph x^4 intersect 2x^2 at 0 and +root 2 and -root 2
so the area bouded by the curve will be max when either a=root2
and b is inf  or b=-inf and a is -root 2

for algebric soln  differentiat
[ a][b ] (X4 -2X 2)dx.   with respect to a and b separatly and apply maxima minima separetly to get appropriate value of a,b separately
 


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iitkgp_bipin (5869)

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When you will draw the curves x4 and 2x2 they intersect at (0,0) ; (2,2) ; (-2,2)

In the 1st quadrant there are two areas one of which is from x = 0 to x = 2 and is bounded and one is unbounded from x = 2 to 

Similarly in the 2nd quadrant there are two areas one of which is from  =0 to x= -2 and is bounded and one is unbounded from x = -2 to -.

Accordingly set your values of a and b for minimum and maximum.

Bipin Kumar Dubey
Chemical Dept.
IIT Kharagpur

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