quadratic equation?

Question

How is a quadratic equation used in everyday life? Can you give an example?

Answer 1

Many examples - particularly from the world of physics and motion where there are physical rules involving squares - are described on this link.

Answer 2

Income = price time number of units sold. Say market research tells you dropping the price $1 per unit increases sales by 10 units, and right now $20 per unit gets you 5000 units sold. Clearly if you raise the price, eventually no one buys and income is 0. But if you drop the price to 0, income is again 0. Somewhere in between, income will be a maximum. So we want to maximize
I = (20 - x)(5000 + 10x), where x is the amount we drop the price.
if x = 20,I = 0; if x = -500, I = 0.

Since the equation is quadratic, it hits a maximum halfway between 20 and -500, which is half of -480 or -240. That means I should raise the price by $240. It will cost me 2400 sales, but $260 times 2600 sales is $676,000, where now I'm only earning $10,000.

If you say making money isn't everyday life, I have to tell you that hanging with friends and listening to music isn't life, it's only childhood.

Answer 3

If a ball is thrown into the air, you can find how high it is after how long it was released. For example, the path of an arrow shot into the air is
h=192t-16t^2
h is the height in feet above the ground
t is the number of seconds after it is released
By using the quadratic equation, you can figure out between what period of time the arrow is above 432 feet.

Answer 4

distance of a ball from the ground when thrown (with repect to time), velocity of ball thrown straight up w/ resp to time