Today, I am giving the three real-life examples of function, sequence, and series. Firstly, I am giving my function as  I have 100 dollars and I want to buy some tennis balls which is five dollars each. My purpose is to calculate how much money left is in my pocket after buying x tennis balls. Since my function is linear (f(x)=100-5x), it does not have a horizontal asymptote.

Secondly, the sports store decide to give prizes. They announce that the more we buy, the more we get! If I buy three tennis balls, I get a ping pong ball for free; if I buy four tennis balls, then I get two…etc. This is therefore a sequence a_{n} =n-n/2 for the amount of ping pong balls. However, we can buy as many tennis balls as you want so that you will also get as many ping pong balls as we can. So that the sequence diverges to positive infinity.

Lastly, when I am going to count the total of ping pong balls I get as prizes, I will have to calculate the series of a_{n}=n-n/2. Since I get more ping pong balls when I buy more tennis balls, the total of ping pong balls is going to be bigger and bigger, so the series is also diverging to positive infinity.