Wednesday, September 17, 2008

September 17, 2008 (Wednesday)

Hey their you guys!! So today we went over the homework assignment from the previous day.

<----- Here is the first question we did in class. To solve this you must use Sin law.

Sin A / a = Sin B/b

* Note before this you must find each angles of the triangle. Assuming that each angle must be 90's as simple as subtracting to find the rest of them. Once you find this you can just add your information to the formula.

Sin 53/1200m = Sin 29/b

0.786/1200m = 0.4539/b -----> cross multiply

1200(0.4539)=o.796b/ o.796

b= 682.8

~ Sin Law is always True if one angle is 90, so are the others.~

*** We corrected the other questions, if you have problems with them don't be afraid to ask for help. Make sure you do your homework!!***

Exercise 5:

So today we did something new.Basically we were finding perfect squares in a trinomial.

4x^2 + 4x +1=0


(2x+1)^2 .'. This is a perfect square



K= 16 .'. This a perfect square

x^2 -5x+k

(x- 5/2)(x- 5/2)

K= 25/4 .'. This is a perfect square

To make a perfect square, your number "c " has to be the square of (b/2) ^2 . It can be any number you like as long as it fit into the equation.

a --- b --- c

c=(A x B/2) ^2 .....this makes a perfect square. Though in some cases it's different.

(2x+1) (2x+1)

(2x+1)^2 In this case. (A x C)= (4/2)^2

Perfect squares are easy you just need to factor it out. Note that you don't need to know about A x C= (4/2)^2 or (b/2)^2 . They are just up here for the benefit of knowledge.

After learning about perfect squares we looked ahead into Exercise 6. Their we discussed question one on that page.
Finding the biggest area of a rectangle. Say they give you 80 m of fencing. Your length and width would be 20m. why? because when you add 2x +2y= 80m .... a.k.a 2(20) + 2(20)= 80m

Sorry If their were any errors on here, I'm not really good at explaining things, especially math.The homework For tonight is Exercise 5 , and the next blogger is :

1 comment:

camiLLe said...

kayla good job!!,and its very colorful:Dtnx