Blaine's post for Nov 14/2011

Hi everybody, I'm Blaine and I'm going to be explaining the use of the quadratic formula as best as I can.


First of all, this is the quadratic formula: 

X=(-b±sqrtb^2-4ac)/2a, Please note that sqrt means square root :)

With this formula, we can solve any equation that CAN'T be factored. So lets do an example from the book.

Ex) 2x^2-6x-7=0

Before we start anything lets state what our a, b, and c values are: a=2, b=-6, c=-7

Ok, Now that that's done, we substitute the values into the equation

X= (-(-6)±sqrt(-6)-4(2)(-7))/2(2)

Now, we add the values inside the square root together, and change the sign in front of the first value accordingly, and also multiply the 2 by the a value in the denominator

X=(6 ±sqrt36+56)/4

Simplfy a little more

X=(6±sqrt92)/4

And now because of the "±" this formula has two different answers

X=(6+sqrt92)/4 or X=(6-sqrt92)/4

And considering the answers of these are not exactly clear, We'll leave them like this :)

There you go, that's how you solve a equation using the quadratic formula, Hope you liked this post and found it helpful

P.S sorry there are no pictures, I just thought it would be easier to type everything, but here's a video from khan academy that basically explains the whole quadratic formula process :)

AND also here's a interesting/short video on binary numbers :)