I'm studing that relationship but i cant figure out how to solve a simple problem from my book:

What is the highest frequency component in the output of an integrator with t=10 micro seconds? assume the 5t < tw.(5 time constanst is < than pulse width).

i know the formula fh = 0.35/tr, but my answer is not right, any idea?.

the book answer is 15.9 khz, but i dont know how to achieve that result.

please excuse my poor english and thanks for any help.