Menghitung Fungsi Permintaan dan Penawaran | Ekonomi Kelas X SMA/MA | EDURAYA MENGAJAR

Summary

The video explains the concepts of demand and supply functions through relatable shopping examples. It begins by showing how discounts and free shipping in online shopping can influence purchase quantity, illustrating the demand function. It then shifts to how a seller, like the viewer’s mother selling clothes, adjusts sales behavior based on price changes, demonstrating the supply function. The video walks through the formula for calculating demand and supply, with a detailed example of price and quantity changes when buying shirts, and simplifies the explanation using a 'cross multiplication' method for easier understanding.

Takeaways

• 🛒 Flash sales and free shipping can encourage people to buy more items online due to the perceived value.
• 📉 The speaker contrasts how a buyer reacts to lower prices (buying more) with how a seller reacts to higher prices (selling more for profit).
• 🧮 The relationship between price and quantity is explained through demand and supply functions.
• 💡 The demand function helps understand how price changes affect the quantity demanded by consumers.
• 💼 The supply function illustrates how price changes influence the amount of goods sellers are willing to offer.
• 📊 The key variables in the functions are price (P), initial price (P1), changed price (P2), quantity (Q), initial quantity (Q1), and changed quantity (Q2).
• 🔢 A step-by-step method is introduced for calculating demand and supply functions using given data points on price and quantity.
• 🧾 A detailed example is provided, where the buyer purchases 200 units at a price of Rp100,000, and later buys 400 units when the price drops to Rp80,000.
• 📉 The derived demand function in the example is: P = -100Q + 120,000, or inversely, Q = -1/100P + 1200.
• 🚀 A shortcut method is shared to simplify the process, by focusing on the differences between prices and quantities to quickly derive the demand function.

Q & A

What is the main topic discussed in the video script?

The main topic discussed is the concept of demand and supply functions, explained through real-life examples like online shopping and selling clothes.

How does the script illustrate the concept of the demand function?

The script explains the demand function by showing how a person buys more products (t-shirts) when the price drops during a flash sale.

How is the supply function demonstrated in the script?

The supply function is demonstrated by showing how the speaker’s mother sells more clothes when prices rise to gain more profit and sells less when prices decrease.

What is the significance of the variables P, P1, P2, Q, Q1, and Q2 in the script?

P represents the price, P1 is the initial price, P2 is the changed price, Q represents the quantity, Q1 is the initial quantity, and Q2 is the changed quantity in the demand and supply functions.

What does the formula for demand and supply functions help us understand?

The formula helps in understanding the relationship between price changes and the quantity of goods demanded or supplied.

In the example provided, what were the values of P1, P2, Q1, and Q2?

In the example, P1 (initial price) was Rp100,000, P2 (new price) was Rp80,000, Q1 (initial quantity) was 200 units, and Q2 (new quantity) was 400 units.

What is the process for calculating the demand function according to the script?

The process involves substituting values into the formula, calculating the differences between P1, P2, Q1, and Q2, and solving for the demand function using cross-multiplication.

What is the final demand function derived from the example?

The final demand function derived from the example is Qd = -1/100P + 1200.

What does the simplified method of solving the demand function involve?

The simplified method involves calculating the difference between P2 and P1, and between Q2 and Q1, then cross-multiplying the values to get the demand function.

Why is understanding the demand and supply function important in real life?

Understanding the demand and supply function is important because it helps in predicting how changes in price affect the quantity of goods bought or sold, which is crucial for both consumers and sellers.