# Question:I have an equation (after dsolve), how can I use only one part of it (to see when the solution becomes equal to smth)?

## Question:I have an equation (after dsolve), how can I use only one part of it (to see when the solution becomes equal to smth)?

Maple

I have a differential equation.

ODE := diff(diff(x(t), t), t)+.2*(diff(x(t), t))-x(t) = sin(t)

ics := x(0) = .5, (D(x))(0) = 5

X1 := dsolve({ODE, ics})

So the solution is:

X1 := x(t) = exp((1/10*(-1+sqrt(101)))*t)*((111/404)*sqrt(101)+111/404)+exp(-(1/10*(1+sqrt(101)))*t)*(111/404-(111/404)*sqrt(101))-(5/101)*cos(t)-(50/101)*sin(t)

Now I need to find out when the solution becomes equal to 1.

But Maple of course does not understand when I write

S1:=min(solve(X1=1,t) assuming t>0)

and throws an error, because X1 is an equation, not an expression.

SO THE QUESTION IS:

How can I explain that I want to use only a right part of X1 in

solve(X1=1,t)

?

Thanks a lot

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