Latest TCS Aptitude Question SOLUTION: The maximum possible value of (5^x - 25^x) over all real values of x is a.0 b.1/2 c.1 d.1/4 infinity

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The maximum possible value of (5^x - 25^x) over all real values of x is

a.0
b.1/2
c.1
d.1/4
infinity

Asked In TCS Gourav Jaiswal (11 years ago)

Unsolved Read Solution (9)

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Read Solution (9) :

manibabu  (11 years ago)

answer is 0..
the maximum value of that expression is 0 when x=0.
no other value of x gives neither infinity or any positive number.

Is this solution Helpfull? Yes (15) | No (4)  

Jamal h mallik  (11 years ago)

5^-5-25^-5 = 0.00
5^-4-25^-4 = 0.00
5^-3-25^-3 = 0.01
5^-2-25^-2 = 0.04
5^-1-25^-1 = 0.16
5^0-25^0 = 0.00
5^.5-25^.5 = -2.76
5^0.25-25^0.25 = -0.74
5^1-25^1 = -20.00
5^2-25^2 = -600.00
5^3-25^3 = -15500.00
5^4-25^4 = -390000.00
5^5-25^5 = -9762500.00

perfect ans is -1 depending on the option it would be 0

Is this solution Helpfull? Yes (10) | No (3)  

ashish  (11 years ago)

ans 1/4....differentiate the given eq then equate to zero...we get 5^x=1/2....putting this on given eq we get..1/4

Is this solution Helpfull? Yes (7) | No (2)  

nishant pandey  (11 years ago)

answer is infinity

Is this solution Helpfull? Yes (2) | No (5)  

atla  (11 years ago)

answer is infinity........

Is this solution Helpfull? Yes (2) | No (1)  

sruthi kaipa  (11 years ago)

ans is not zero... the max value that i got is 1/4... if there is any other max value please do update....

Is this solution Helpfull? Yes (1) | No   

sruthi kaipa  (11 years ago)

can u explain how it is infinity? @nishant

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SHANU MAHAJAN  (11 years ago)

my ans is not exactly 1/4 but taking x= -1/2 we get .247
ans can be 1/4

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manoj kumar  (11 years ago)

differentiating the above equation and equating it to zero
5^xlog5-2*25^xlog5=0
5^x=2*25^2x
x=-0.43
by sub x in the equ we get max value as 0.25

Is this solution Helpfull? Yes | No (1)  

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