AP EAMCET201921 Apr 2019Evening ShiftMathematicsApplication of DerivativesActual
If p and q are respectively the global maximum and global minimum of the function f ( x ) = x 2 e 2 x on the interval [ - 2 , 2 ] , then p e - 4 + q e 4 =
Options
- A0
- B4 e 8
- C4
- D4 e 8 + 1
Correct answer
C. 4
Step-by-step solution
It is given that, f ( x ) = x 2 e 2 x Differentiating the above equation we get, f ' ( x ) = 2 e 2 x x 2 + 2 x e 2 x ⇒ 0 = 2 e 2 x x 2 + x ⇒ x 2 + x = 0 ⇒ x = 0 ,   - 1 The maxima and minima is obtained at - 2 ,   - 1 ,   0 ,   2 as the function bound. Thus, f ( - 2 ) = ( - 2 ) 2 e - 4 = 4 e - 4 f ( - 1 ) = ( 1 ) 2 e - 2 f ( 0 ) = 0 f ( 2 ) = ( 2 ) 2 e 4 = 4 e 4 Thus, p = 4 e 4 and q = 0 . p e - 4 + q e 4 = 4 e 4 e - 4 + 0 = 4 e 0 = 4