The number of applications for patents, N, grew dramatically in recent years, with growth averaging about 3.5% per year. That is,N'(t)=0.035N(t) . a) Find the function that satisfies this equation. Assume that t=0 corresponds to 1980, when approximately 121,000 patent applications were received. b) Estimate the number of patent applications in 2015 . c) Estimate the doubling time for N(t).