MCQ
જો $f(x) = {1 \over {\sqrt {{x^2} + {a^2}} + \sqrt {{x^2} + {b^2}} }}$, તો $f'(x) = . . . .$
- ✓${x \over {({a^2} - {b^2})}}\left[ {{1 \over {\sqrt {{x^2} + {a^2}} }} - {1 \over {\sqrt {{x^2} + {b^2}} }}} \right]$
- B${x \over {({a^2} + {b^2})}}\left[ {{1 \over {\sqrt {{x^2} + {a^2}} }} - {2 \over {\sqrt {{x^2} + {b^2}} }}} \right]$
- C${x \over {({a^2} - {b^2})}}\left[ {{1 \over {\sqrt {{x^2} + {a^2}} }} + {1 \over {\sqrt {{x^2} + {b^2}} }}} \right]$
- D$({a^2} + {b^2})\left[ {{1 \over {\sqrt {{x^2} + {a^2}} }} - {2 \over {\sqrt {{x^2} + {b^2}} }}} \right]$