Engineering Board Exam Reviewer · Higher-Order Derivatives · medium
Find d2y/dx2 if y= ≤ft(x2+1 ).
- - 2≤ft(x2 + 1 )2
- 2 x2 - 2≤ft(x2 + 1 )2
- 2 xx2 + 1
- 2 - 2 x2≤ft(x2 + 1 )2
Answer
D. 2 - 2 x2≤ft(x2 + 1 )2
Solution
y'=2x/x2+1. By the quotient rule, y''=2(x2+1)-2x(2x)/(x2+1)2=2-2x2/(x2+1)2.