Sunday, April 1, 2012

how do we put all of our quadratic knowledge together?

Now that we know so much about quadratics its time to see what we have learned *if you forgot some of the it don't worry i will post links to my quadratic posted at the bottom each link has more links in them for more help and reviews *
if you remember the formula then this will be easy. if we have x^2+3x-4we want to know what is the Vertex X and Y  intercept and Roots
we first will use the formula  *remember ax^2+bx+c* 
x = -3± √(3^2-4(1)(-4))/2(2)
x=-3± √(9+16)/4
x=-3± √25/4
x=-3± 5/4
we are left with X=-4,1
Vertex:(-2,-6)
X intercept:(-4,0)(1,0)
Y intercept:(0,4)
Roots:(-4,0)(1,0)




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how do we review inequalities

inequalities is pretty basic.Having an inequality problem like 2x+10<14 is the same as 2x+10 = 14.
We want to get x by it self so we substrate 10 from both sides.
We get 2x < 24 now, we divide 2 from both sides we get x <12 on a number line the twelve will have a open circle and the line will go to the left side.
Now lets try a harder one for example 2x+3y<15
First we try to get y by it self so we substrate 2x from both sides we are left with 3y<-2x+15
Now divide by 3 to get y<2/3x+5
x < n when the sign is like this you have open circle and we shade to the left.
x < n when the line is under the less then sign then the circle is closed with  the shade going to the left.
x > n when the sign  is like this one the circle is open with the shaded line going to the right.
x > n and finally when the greater sign has the line under the circle is shaded and the shaded line goes to the right.
now that you guys have a understanding check out the link below for more problem:
and for more help check out the two other links:
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