Calculates an investment's internal rate of return using a series of periodic cash flows.
IRR(сashflowamounts: Array, rateguess: Number = 0.1) => Number
A list containing the income or payments associated with the investment.
An estimate for what the internal rate of return will be.
array1 = [-20000,-1000,9000,15000]array2 = [-100000,-80000,-40000,10000,80000,100000,150000]