What is a Quadratic Equation?


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Let's take a look at an example


The setup cost for the project to develop a new tank design is 50 thousand dollars. The development cost is a function of time. In other words, the cost increases with time. From previous contracts, the cost function is estimated to be

where t is the time measured in working days. Suppose that a cost analyst has 650 thousand dollars allocated for the project, and he/she wants to know how long before he/she needs to allocate more resources to complete the project?



Let's consider a solution



The total cost for the tank is equal to the sum of the initial cost and the development cost.




If $650 thousand has been given, we want to know how much time before more resources needs to be allocated?



If we move 650 to the left of the equal sign, this is what we have



To solve the equation above, we just factor the terms as follow:



The equation yields two answers: t = -20 and t = 30. Since negative time has no physical meaning, t = 30 is the only valid solution



It takes 30 working days before the cost analyst needs to allocate more resources to fund the project.



A few simple facts that you should know



Did you know that the above example has a quadratic equation?



What is a quadratic equation anyway?


A Quadratic Equation is a polynomial equation in which the highest power of the unknown variable is 2. The most common form of a quadratic equation is an equation where the right hand side is usually set to zero and that the highest exponent of any unknown variable is 2.


                              
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