NDA2017MathematicsDifferentiationActual
What is d^2 x d y^2 equal to?
Options
- A- ( d^2 y d x^2 )⁻¹ ( d y d x )⁻³
- B( d^2 y d x^2 )⁻¹ ( d y d x )⁻²
- C- ( d^2 y d x^2 ) ( d y d x )⁻³
- D( d^2 y d x^2 )⁻¹
Correct answer
C. - ( d^2 y d x^2 ) ( d y d x )⁻³
Step-by-step solution
Let y = f ( x ) dy dx = f ^1( x ) dx dy = 1 f ^ ( x ) aligned & d^2 x d y^2 = -d d y f^ (x) (f^ (x) )^2 ...(i) & -d d y f^ (x) (f^ (x) )^2 = -d d y ( d y d x ) d x d x (f^ (x) )^2 = -d d x (f^ (x) ) d x d y ( d y d x )^2 & -f^ (x) d x d y ( d y d x )^2 = - ( d^2 y d x^2 ) ( d y d x )^3 = -d^2 y d x^2 ( d y d x )⁻³ aligned