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The solution of the differential equation ` (dy)/(dx) - (tany)/x = (tan y sin y)/(x^(2))` isA. `x/(siny) + log x = C`B. `y/(sin x)+log x =C`C. `log x +x = C`D. `log x +y = C` |
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Answer» Correct Answer - b Given , ` (dy)/(dx) - (tany)/x = (tany sin y )/(x^(2))` ` rArr coty " cosec " y (dy)/(dx) - ("cosec "y)/x = 1/(x^(2))` Put ` - " cosec " y = t` ` rArr cot y " cosec " y (dy)/(dx) = (dt)/(dx)` Eq. (I ) reduces to , ` (dt)/(dx) +t/x = 1/(x^(2))` ` IF = e^(int P dx) = e^(int 1/x dx)= x` ` :. ` Required solution is given by ` tx = int x * 1/(x^(2)) dx- C` `rArr - "cosec" y * x = log x = C` ` rArr x/(sin y) + log x = C ` |
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