Help please answer this question thank you

Problem 7 Consider an uncharged, circular parallel plate capacitor with radius R. Assume that the plates are sufficiently large and can be approximated as infinite. A voltage, and therefore a current I, is induced on the plates, generating a net charge on the plates which changes a function of time. For this problem, assume that there is vacuum between the plates of the capacitor. B E R I I (a) Find an expression for the time derivative of the electric field within the parallel plate capacitor as a function of I, R and universal constants. (b) Find the time derivative of the electric flux through an area with radius r > R and r R and r