Manipal MET2020MathematicsApplication of Derivatives
If f^ (x) 0 x R, f^ (3)=0 and g(x)=f ( ^2 x-2 x+4 ), 0 x 2 , then g(x) is increasing in
Options
- A(0, 4 )
- B( 6 , 3 )
- C(0, 3 )
- D( 4 , 2 )
Correct answer
D. ( 4 , 2 )
Step-by-step solution
Given, g(x)=f ( ^2 x-2 x+4 ) On differentiating w.r.t. x , we get aligned g^ (x)=f^ ( ^2 x-2 x . & +4) & (2 x ^2 x-2 ^2 x ) aligned =f^ ( ^2 x-2 x+4 ) 2 ^2 x( x-1) f^ (x) 0 x (0, 2 ) Also, 2 ^2 x 0 x (0, 2 ) [ x (0, 2 ) . , given ] But x-1 0 x ( 4 , 2 ) g^ (x) 0 x ( 4 , 2 ) Hence, g(x) is increasing in ( 4 , 2 ) .