Calculus problems

An annuity pays out $10000 per year. Because of inflation, each year one dollar is worth what $0.98 was worth the previous year. The payment is made at the beginning of each year. What is the present value of the annuity if it pays out for three years (starting immediately)? Preview what is the present value of the annuity if it pays out for ten years? Preview what is the present value of the annuity if it pays out forever? Preview