微積分問題,高手請進(求助:身在國外)

小的身在國外

問題是英語寫的

希望大大見諒請寫出過程和答案1.)Between 1995 and 2001

the revenue of Sears Roebuck and Co. can be modeled as R(t)=(11.24)/(1 1.366e^-1.55t) 30 billion dollars per year

where t is the number of years after 1995. Assume that the revenue can be reinvested at 6.5% compounded annually. If Sears Roebuck and Co. invested in this manner until the year 2003

what would be the present value of their investment? Round your answer to the nearest $10 billion.2.)Evaluate the improper integral if it coverges

or state that it divergesThe integral is from(-infinite)to(-2)

the model is (3x^3)/((X^4) 1)3.) Cash Machines. The number of minutes between arrivals of customers at an automated teller machine is exponentially distributed with a mean of 9 minutes. If a customer