NDA2015MathematicsDifferentiationActual
Given that d d x ( 1+x^2+x^4 1+x+x^2 )=A x+B What is the value of A?
Options
- A–1
- B1
- C2
- D4
Correct answer
C. 2
Step-by-step solution
Given d d x ( 1+x^2+x^4 1+ x + x ^2 )= d dx [ 1+ x + x ^2+ x ^4- x 1+ x + x ^2 ] aligned & = d d x [1+ x^4-x x^2+x+1 ] & = d d x [1+ x (x^3-1 ) x^2+x+1 ] & = d d x [1+x(x-1)] & = d d x [1+x^2-x ]=2 x-1...(i) aligned Now comparing equation (i) with AX + B , we get A =2 and B =-1 .