September 28, 2010

Hi everybody it's Mae-lyn,

Today in precal we had a short class because we had T.A. Mr. Piatek showed us a photo of a valley in Colorado with a bridge, which looked like an upside down parabola. He showed us this photo because, we have a project about photos relating to precal. Also, Mr. Piatek mentioned that today was his father's name day and that his is on December 19. Mr. Piatek also said he didn't receive many presents on Christmas because his name day was to close to Christmas. So today, we learned how to complete the square, when the coefficient "a" was equal to more than 1.

Here is an Example  

y = 2x² + 4x +3

The first thing you do is change the "y" to a 0, which is 0 = 2x² + 4x +3
then, move the 3 over to the other side of the equation to equal -3 = 2x² + 4xnext you factor out the 2 making the equation -3 = 2(x² + 2x)after this you complete the square by dividing the b value which is 2, in this equation and divide it by 2. Then square your answer, and it should look like this -3 = 2(x² + 2x +1)
then you take the answer you just got and multiply it by the coefficient which equals 2. (2x1=2)  Then add it to the -3 on the other side of the equation to be -3 + 2 = 2(x² + 2x +1)
now you can do the math on the left side of the equation, which would equal -1. And then on the right, write the square as a binomial making it -1 = 2(x + 1)²
then move the -1 to the other side of the equation which the 1 turns positive like this 0= 2(x+1) +1.
Lastly you write the equation to equal y so you replace the 0 with a "y", and your final answer is  y = 2(x + 1)² + 1


HOMEWORK: The blue booklet up to pg. 33, and work on your assigment booklet (review)

*Start studying for the test on Friday!