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    Geometry-Sequences with unlimited repeated values

    Here is the question I cannot get it.... In a series of license plates, the first three symbols are any of the 26 letters in the alphabet and the last three are any of the 10 digits from 0 to 9. How many plates can be formed in which at least one symbol is repeated? - --------I know that...
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    Help with a Proof

    i'm lost :(
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    Help with a Proof

    I don't know man I'm frigging confused... so you saying that A+B+C+D=360?
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    Help with a Proof

    Prove that the sum of the exterior angles at opposite vertices of any quadrilateral es equal to the sum of the interior angles at the other two vertices. THIS question is REAly really really really getting me frustrated... The way we're suppost to do it is like this.... 180n-360 is the...
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    Completing the Square

    Yea thanks Dan for your help I now clearly understand it.. Btw ya that was a mistake with the -2 , what should have bee +2
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    Completing the Square

    Ok so can you please tell me where I go wrong here. I want to put y=3x^2+2x-1 into y=a(x-h)^2+K ax^2-2ah+ah^2+k=3x^2-2x+ah^2-1 ax^2=3x^2 -----> a=3 -2ahx=-2x -2(3)hx=-2x ----->h=1/3 K=----->-1 Therefore: y=3(x-1/3)^2-1 But I think it's suppost to be: y=3(x+1/3)^2-4/3 Is...
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    Grrrr Help would be appreciated

    yea I just saw at the back of the book it said (5,6) and I had no idea where that came from
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    Intersection of Two Lines

    yea i''m really struggling with this one.... I understand that if you change 10x+4y-101=0 to y=(101-10x)\4 that the direction vector for that line would be (4,-10) am I right? then since they are perpendicular I would take the point (3,-4) and subract it to make the direction vector for...
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    Cartesian Equations

    Find the Cartesian equation of each of the following lines. (x,y)=(4,-6) + t(8,2) Not sure how to do it, I know that you need the normal which is (-2,8) I've tried alot of times and I don't get it
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    Grrrr Help would be appreciated

    for each of the following, find a point on each line: x=5 :D LOl ok this is what i thought x+0y-5=0 so direction vector=(0,1) If I set x to 5 then y should = 0 shouldn't it?
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    Easy Math question

    :wink: got it :D
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    Easy Math question

    ok I completely Understand it now....But your explanation aswell as mine is purely based on Logical reasoning. Don't you have to set y=0 to find an x intercept?
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    Easy Math question

    Ok I get everything from the beginning, and I know I'm retarded I should have understood that. What is making me confused is the y=1+6t part. that comes from the vector equation r=(6,1)+t(0,6) Why do you even need to know the y=1+6t part? How do you check from that? I originaly thought you...
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    Easy Math question

    Find the points where each of the following lines intersects the x and y axes, x=6,y=1+6t for some reason I don't know how to find the point. If I graph it I understand but I can't work it out.
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    Intersection of Two Lines

    yea but i'm doing geometry and you was is like going back to grade 10.....We learned vectors and probably have to do it taht way
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    Intersection of Two Lines

    lol can someone help me further :(
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    Intersection of Two Lines

    ok i don't get how you get y= (2/5)(x-3)- 4 can't you do (x-3,y+4)dot(2,5)= 0 and then substitute can't I also write it as r=(3,-4)+t(2,5)????? LOL i tried doing it my way and i got as an answer to be (187/14,-171/21)
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    Intersection of Two Lines

    I have tried but doesn't work out well.... Find the point at which the normal through the point (3,-4) to the line 10x+4y-101=0 intersects the line. Originaly I thought that it should be found by doing the dot product of: (x-3,y+4)dot(-4/10,-10/4)= 0
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    Equation of a Line in three space question

    Ok let me show you how i think it's to be done because I don't get your part of "That equation, together with the equations (x-11)/3=(y+8)/-1=(z-4)/1 is enough to solve for x, y, and z and then the equation of the line." r=(11,-8,4)+t(3,-1,1) r1=(4,5,5)+t(x,y,z) r dot r1=...
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    Equation of a Line in three space question

    direction vector=(3,-1,1)
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    Equation of a Line in three space question

    This question is really pissing me off because I don't understand it. I know how to do it but don't understand the reasoning: Find an equation of the line through the point (4,5,5) that meets the line (x-11)/3=(y+8)/-1=(z-4)/1 at right angles. I found out that you have to do the dot...
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