Ok so i didnt think about school all this week so i forgot about the whole blog and comment thing so ima come do this right now to make it up. Im going to talk about something that gives me problems and is from chapter 1....graphing parabolas. Its not so much that its hard it just that i forget how to find x intercept, y intercept, vertex and axis of symmetry. so ill talk about this as best as i can.
There are 7 steps to this: 1. finding what way it opens, 2. how many intercepts, 3. finding the x intercepts, 4. finding y intercepts, 5. finding the axis of symmetry, 6. finding the vertex, and 7. graphing the parabola. to find the opening, you have to look infront of the x^2...if the number is positive then it opens up, if negative it opens down.
To find how many intercepts you plug in the formula b^2-4ac.
I kinda dont understand how to find x intercepts but i think you do completing the square .
when finding the y intercepts, you plug 0 in for x and solve for y.
to find the axis of symmetry you plug in the formula x=-b/2a
for the vertex you plug in your answer of the axis in for x and solve
then you just plug your answers in on a graph and you should get a parabola, if you dont know how to do this then you can use ur calculator
As said before im a little fuzzy on how to do these steps so if someone would be able to help or correct what i wrote if wrong then i would be grateful.
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to find an x intercept you solve for X
ReplyDeleteit says that in your question
"find X intercept"
remember "find X"
(dont forget to put answer into point form. when solving for x you will always wind up having to square root. you know this meas the answer will be +/-. be sure to show this when convertine to point form. {I.E. (#,0) & (-#,0)} in many of the problems we had there was also a matter of carring a number to the other side. this is no big deal you just tack it on also. for example... if you ended with
X-2= +/- square root 6/2
you would add 2 to both sides and put in point form. therefore you'd have
(squareroot 6/2+2,0) & (- squareroot 6/2+2,0))