MHT CET2017MathematicsDifferentiation
If x = f ( t ) and y = g ( t ) are differentiable functions of t then d 2 y d x 2 is
Options
- Af ′ ( t ) ⋅ g ″ ( t ) − g ′ ( t ) ⋅ f ″ ( t ) [ f ′ ( t ) ] 3
- Bf ′ ( t ) ⋅ g ″ ( t ) − g ′ ( t ) ⋅ f ″ ( t ) [ f ′ ( t ) ] 2
- Cg ′ ( t )   ⋅   f ″ ( t ) − f ′ ( t )   ⋅ �
- Dg ′ ( t )   ⋅   f ″ ( t ) + f ′ ( t )   ⋅   g &
Correct answer
A. f ′ ( t ) ⋅ g ″ ( t ) − g ′ ( t ) ⋅ f ″ ( t ) [ f ′ ( t ) ] 3
Step-by-step solution
X = f ( t ) Y = g ( t ) d x d t = f ′ ( t ) d x d t = g ′ ( t ) d y d x = d y d t d x d t = g ′ ( t ) f ′ ( t ) d 2 y d x 2 = d d x ( g ′ ( t ) f ′ ( t ) ) = d d t ( g ′ ( t ) g ′ ( t ) ) . d t d x = f ′ ( t ) ⋅ g ″ ( t ) − g ′ ( t ) ⋅ f ″ ( t ) ( f ′ ( t ) ) 2       ⋅ 1 f ′ ( t ) = f ′ ( t ) ⋅ g ″ ( t ) − g ′ ( t ) ⋅ f ″ ( t ) ( f ′ ( t ) ) 3