Integrals — Class 12 Maths Solution

ncert exercise SA NCERT,ex.7.9,Q.21,Page 338
Question

$\int\limits_1^{\sqrt 3 } {\cfrac{{dx}}{{1 + {x^2}}}}$ equals

  • (a) $\cfrac{\pi }{3}$
  • (b) $\cfrac{{2\pi }}{3}$
  • (c) $\cfrac{\pi }{6}$
  • (d) $\cfrac{\pi }{{12}}$
Step-by-step Solution

Option d is correct

Let$I = \int\limits_1^{\sqrt 3 } {\cfrac{{dx}}{{1 + {x^2}}}} = \left[ {{{\tan }^{ - 1}}x} \right]_1^{\sqrt 3 }$

$= {\tan ^{ - 1}}\sqrt 3 - {\tan ^{ - 1}}\left( 1 \right) = \cfrac{\pi }{3} - \cfrac{\pi }{4} = \cfrac{\pi }{{12}}$

NCERT & Exemplar solution for CBSE Class 12 Mathematics, Integrals. Curated by Sachin Sharma. Free for all students.