defence exam Agniveer Vayu Group X & XY Mock Test 01/2026 Mathematics Differential Calculus Evaluation of derivatives
If \( y={ \left( \tan ^{ -1 }{ x } \right) }^{ 2 } \), then \({ \left( { x }^{ 2 }+1 \right) }^{ 2 }\cfrac { { d }^{ 2 }y }{ d{ x }^{ 2 } } +2x\left( { x }^{ 2 }+1 \right) \cfrac { dy }{ dx } = \)
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