MCQ
${d \over {dx}}\left\{ {{e^x}\log (1 + {x^2})} \right\} = $
- ✓${e^x}\left[ {\log (1 + {x^2}) + {{2x} \over {1 + {x^2}}}} \right]$
- B${e^x}\left[ {\log (1 + {x^2}) - {{2x} \over {1 + {x^2}}}} \right]$
- C${e^x}\left[ {\log (1 + {x^2}) + {x \over {1 + {x^2}}}} \right]$
- D${e^x}\left[ {\log (1 + {x^2}) - {x \over {1 + {x^2}}}} \right]$
. Then the standard deviation of $a_1, a_2, \ldots, a_{10}$ is equal to :