MCQ
${d \over {dx}}\left[ {\log \left( {x + {1 \over x}} \right)} \right] = $
- A$\left( {x + {1 \over x}} \right)$
- B${{\left( {1 + {1 \over {{x^2}}}} \right)} \over {\left( {1 + {1 \over x}} \right)}}$
- ✓${{\left( {1 - {1 \over {{x^2}}}} \right)} \over {\left( {x + {1 \over x}} \right)}}$
- D$\left( {1 + {1 \over x}} \right)$