Manipal MET2018MathematicsApplication of Derivatives
The function x(1+ x), 0 x 2 has maximum value, when x is equal to
Options
- A0
- B2
- C6
- DNone of these
Correct answer
D. None of these
Step-by-step solution
Let z= x(1+ x) or z= x+ 1 2 2 x On differentiating w.r.t. x , we get d z d x = x+ 2 x For maximum or minimum, put d z d x =0 array rr & x+ 2 x=0 & 2 ^2 x-1+ x=0 & ( x+1)(2 x-1)=0 & x=-1, 1 2 & x array But 0 x 2 , therefore we take only x= 3 . d^2 z d x^2 =- x-2 2 x=- ve , for x= / 3 It is maximum at x= / 3 .