Problem: Using Microsoft Excel, create an investment cash-flow diagram that will have a present worth of zero at MARR = 7%. The study period needs to be exactly 18 years and each year should have at least one unique cash-flow that is different from the cash-flows over the other_years. Your answer should contain a table showing the cash-flows for each year and a graphical representation of the cash-flows (cash-flow diagram). Use Figure. 6 to answer questions ( 18, 19, 20 and 21) t(ms) Figure 6: 18. The voltage v(t) expression is (a) 2cos(500t - 45) (b) 2cos(v/2t - 45) (c) 2cos(500xt+45) (d) 2cos(500- t) (e) 2sin(x/2t) (f) 2sin(1000 t +30) (g) None of the above 19. The Power factor of the circuit is (a) 0.5 Lags (b) 0.5 Leads