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    what am i doing wrong guys...

    (quadratic graphs)

    y = x2 + 2x -3

    for values of x from -4 to 2...

    the y values are right in front of me and im putting the negative x values into my calculator and coming up with incorrect y values?

    why is this guys?

    thanks in advance
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    If you square a negative number, the answer will always be positive.
    On a calculator, if you square a negative number the answer comes up as negative, but this is wrong.
    You can't have a negative square number.
    Hope this helps


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    (Original post by georgelewiss)
    If you square a negative number, the answer will always be positive.
    On a calculator, if you square a negative number the answer comes up as negative, but this is wrong.
    You can't have a negative square number.
    Hope this helps


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    wow just as you posted i found this out myself by typing -4 x -4 in the calculator coming up as 16

    surely this is misleading is people dont know that though?

    thanks for reply bro
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    (Original post by ThePremierLeague)
    what am i doing wrong guys...

    (quadratic graphs)

    y = x2 + 2x -3

    for values of x from -4 to 2...

    the y values are right in front of me and im putting the negative x values into my calculator and coming up with incorrect y values?

    why is this guys?

    thanks in advance
    when entering a negative value into a calculator and squaring it remember to put brackets outside to get a positive number (and hence the correct answer!).
    e.g. instead of typing in -2^2 into your calculator type in: (-2)^2 to give 4 instead of -4.
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    (Original post by ThePremierLeague)
    wow just as you posted i found this out myself by typing -4 x -4 in the calculator coming up as 16

    surely this is misleading is people dont know that though?

    thanks for reply bro
    -4*-4 is 16, people do know that; you probably haven't learnt it.
    Have a look at this site: http://www.cimt.plymouth.ac.uk/proje...5/bk7_15i2.htm
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    (Original post by nm786)
    when entering a value into a calculator and squaring it remember to put brackets outside to get a positive number (and hence the correct answer!).
    e.g. instead of typing in -2^2 into your calculator type in: (-2)^2 to give 4 instead of -4.
    thanks dude
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    Put brackets around the number then square all
 
 
 
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