Low pass filter circuit questions

[thenerveman]

Homework Statement

Why does a low pass active filter give a constant gain and no filtering when the capacitor is removed? What type of circuit does this become? Support your answer with equations.

also

Does the amplitude eventually roll off as the frequency was increased toward to a very large value? how would you determine this value? Why does this occur?

Homework Equations

not sure

The Attempt at a Solution

i don't know where to start really. Our professor is a week behind in his lectures and he assigned this.. I am stuck on these two questoins.

 

[NascentOxygen]

Search for a low pass filter constructed around an OP-AMP.

 

[technician]

The capacitor is the frequency dependent component and, as nascent oxygen has indicated, an op amp has some frequency dependency