KCET2011MathematicsTrigonometric Ratios & Identities
If y= x 2 x 3 x n x , then y^ is
Options
- A_ k=1 ^ n k k x
- By _ k=1 ^ n k k x
- Cy _ k=1 ^ n k k n
- D_ k=1 ^ n k x
Correct answer
B. y _ k=1 ^ n k k x
Step-by-step solution
Given, y= x 2 x 3 x . n x . Taking log on both sides, y= x+ 2 x+ + n x Differentiating w.r.t. x , 1 y d y d x =1 x+2 2 x+ +n n x array ll & d y d x =y _ k=1 ^ n k k x & y^ =y _ k=1 ^ n k k x array