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    I'm really confused by this question and have attempted it so many times but have gotten it wrong every time.

    Here it is:
    Point A is (1,1)
    Point B is 2√10 units from A and lies on the intersection of two grid lines.
    Write the coordinates of both possible positions for B.

    I don't know how to even start. Can someone help please?
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    (Original post by Siliac)
    I'm really confused by this question and have attempted it so many times but have gotten it wrong every time.

    Here it is:
    Point A is (1,1)
    Point B is 2√10 units from A and lies on the intersection of two grid lines.
    Write the coordinates of both possible positions for B.

    I don't know how to even start. Can someone help please?
    let's call the co-ordinates of B (c, d). So using the info about units, you can set up one equation... (think about working out the distance between two points)

    Now the grid line info bit, I think wants you to use the fact that the co-ordinates are both integers. So if I had two integers c and d, there is some number k such that c = kd. For example, if we found c = 10, d = 2 then k = 5. Similarity, if c = 2 and k = 3 then d = 2/3.

    So how can you use that c = kd?
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    (Original post by Kevin De Bruyne)
    let's call the co-ordinates of B (c, d). So using the info about units, you can set up one equation... (think about working out the distance between two points)

    Now the grid line info bit, I think wants you to use the fact that the co-ordinates are both integers. So if I had two integers c and d, there is some number k such that c = kd. For example, if we found c = 10, d = 2 then k = 5. Similarity, if c = 2 and k = 3 then d = 2/3.

    So how can you use that c = kd?
    I don't know how exactly I can use the c = kd. I've tried using Pythagoras because it's on a graph so it should be able to be used to get more information that I could use with c = kd but I don't think that it's going to be very useful at all.

    (c-1)^2 + (d-1)^2 = (2√10)^2
    (c-1)^2 = (2√10)^2 - (d-1)^2
    c^2 - 2c + 1 = 40 - (d^2 - 2d + 1)
    c^2 - 2c + 1 = 40 - d^2 + 2d - 1
    c^2 - 2c + 1 = 39 - d^2 + 2d
    c^2 - 2c = 38 - d^2 + 2d
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    (Original post by Siliac)
    I don't know how exactly I can use the c = kd. I've tried using Pythagoras because it's on a graph so it should be able to be used to get more information that I could use with c = kd but I don't think that it's going to be very useful at all.

    (c-1)^2 + (d-1)^2 = (2√10)^2
    (c-1)^2 = (2√10)^2 - (d-1)^2
    c^2 - 2c + 1 = 40 - (d^2 - 2d + 1)
    c^2 - 2c + 1 = 40 - d^2 + 2d - 1
    c^2 - 2c + 1 = 39 - d^2 + 2d
    c^2 - 2c = 38 - d^2 + 2d
    Hmm... that didn't lead where I thought it would. Sorry!
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    (Original post by Siliac)
    I'm really confused by this question and have attempted it so many times but have gotten it wrong every time.

    Here it is:
    Point A is (1,1)
    Point B is 2√10 units from A and lies on the intersection of two grid lines.
    Write the coordinates of both possible positions for B.

    I don't know how to even start. Can someone help please?
    You have a coordinate of B on the x axis and another on the y axis so you have coordinates (0,p) and (p,0). (p is a random letter btw) You know that A is either 1 across from B or 1 above B and you also know that the total distance is 2sqrt10. Can you use these two numbers to find the other distance?
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    (Original post by Siliac)
    I'm really confused by this question and have attempted it so many times but have gotten it wrong every time.

    Here it is:
    Point A is (1,1)
    Point B is 2√10 units from A and lies on the intersection of two grid lines.
    Write the coordinates of both possible positions for B.

    I don't know how to even start. Can someone help please?
    You can create a circle of points which are a distance of 2\sqrt{10} from the point (1,1) by saying that the equation of it is x^2+y^2=40 (around the point (1,1)))

    Now, you want to just pick two pairs of numbers (a,b) such that a,b are whole numbers that satisfy a^2+b^2=40.

    Once you find them, the coordinates of B are just (1+a,1+b) for each pair.
 
 
 
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