Dear teacher, i have this discussion and i need your help with reference

In computing the cost of capital, which sources of capital should be considered? Why do firms calculate their weighted average cost of capital? As the financial manager for your company, explain how you would use the cost of capital of your firm, or a firm you are familiar with, to determine the required rate of return on investment opportunities. Search the SDL or the internet for an academic or industry-related article. Select an article that relates to cost of capital and doing business in Saudi Arabia.