vpasolve() gives wrong solution

I am trying to find the time at which my equation equals a value, but whenever I use vpasolve I am given a completely wrong answer of a negative time value. When I also add t>0 it gives no answer even though the function does equal that value at some positive t value.

syms s t
y(s) = 36/(s*(s^2+2*s+36));
response(t) = ilaplace(y(s))

s = vpasolve(response == 0.1)
st = vpasolve(response == 0.1, t>0)

response(s)

response(t) =

1 - exp(-t)*(cos(5.9161*t) + 0.1690*sin(5.9161*t))

s =

-226.9853

st =

Empty sym: 0-by-1

ans =

-1.0328e+62

You can see that when I try and use solve() without a specific time domain, I receieve a value S that when I plug back into response() is wildly off the value I am looking for. I know for a fact that the function response(t) does cross the value 0.1 in the positve time domain, I have graphed it.

Answer 1

[Walter Roberson]

s = vpasolve(response == 0.1, 0.07)

[John Arbolino]

This works thanks! Where is the default starting value, because I assumed it would be zero.

[Walter Roberson]

I think the default start is 0. However, 0 is not a good starting point for this particular equation.