Question

The points of extrema of f(x) = $\int _ { 0 } ^ { x } \frac { \sin t } { t }$ dt in the domain x > 0 are –

• A. (2n + 1) $\frac { \pi } { 2 }$, n = 1, 2......
• B. (4n + 1) $\frac { \pi } { 2 }$, n = 1, 2......
• C. (2n + 1) $\frac { \pi } { 4 }$, n = 1, 2......
• D. np, n = 1, 2

Answer 1

Answer: (D)

np, n = 1, 2

Answer 2

f '(x) = Ž f ''(x) = $\frac { x \cos x - \sin x } { x ^ { 2 } }$

for max^m/min^m = = 0

Ž sinx = 0 Ž x = np, n 1,2,3