

InterviewSolution
Saved Bookmarks
1. |
If `y(x)`is a solution of thedifferential equation `((2+sinx)/(1+y))(dy)/(dx)=-cosx`and `y(0)=1`, then find the value of `y(pi/2)dot` |
Answer» Given that, `((2+sin x)/(1+y))(dy)/(dx)=-cos x` `Rightarrow (dy)/(1+y)=-(cosx)/(2+sinx)dx` On integrating both sides, we get `int(1)/(1+y)dy=-int (cos x)/(2+sinx)dx` `Rightarrowlog(1+y)=-log(2+sinx)+logC` `Rightarrow log(1+y)+log(2+sinx)=logC` `Rightarrow log(1+y)(2+sinx)=logC` `Rightarrow (1+y)(2+sinx)=C` `Rightarrow 1+y=(C)/(2+sinx)` When, x=0 and y=1, then `1=(C)/(2+sin x)-1` `Rightarrow C=4` On putting C=4 in Eq (i) we get `y=(4)/(2+sinx)-1` `y((pi)/(2))=(4)/(2+"sin"(pi)/(2))-1=(4)/(2+1)-1` `(4)/(3)-1=(1)/(3)` |
|