Could you calculate the component cost of equity for a stock with non constant expected growth rates

Question:

Could you calculate the component cost of equity for a stock with non constant expected growth rates in dividends if you didn't have the information necessary to compute the component cost using the CAPM? Why or why not?

Cost Of Equity
The cost of equity is the return a company requires to decide if an investment meets capital return requirements. Firms often use it as a capital budgeting threshold for the required rate of return. A firm's cost of equity represents the...