Q9 of 137 Page 19

#Mark the correct alternative in each of the following

The sum of two non-zero numbers is 8, the minimum value of the sum of their reciprocals is


Let the two non zero numbers be x and y.


so,x+y=8


y=8-x


and,


put y=8-x in f(x,y)


therefore it will become a function in



f’(x)=0



⇒ x=8-x


x=4



Hence by second derivative test


f’’(x)>0 so it’s a point of minimum.



Hence at x=4 minimum value





Option(B)

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