ATAR Notes: Forum
VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: Visionz on April 24, 2010, 09:35:02 pm
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I need help.
Is y=ax+b the same as y=a+bx? In class we used y=ax+b but the textbook like to use the other one "because thats what statisticians do".
Now after looking at it all again I think my answers are wrong. Like I have been putting the A value where the B value should be.
eg. y=a+bx ... push-ups = 1 + 2 x sit-ups but the back of the book using y=a+bx would have something like push-ups = 2 + 1 x sit-ups. Can I just change the order of it after using y=ax+b so i fits y=a+bx, is A always the intercept and B always the slope? Im just really confused.
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i think u should stick with what works best..the book is differnet in many ways. subbing the values according to their variables and swapping it because the alphabet values r rearragned willl only confuse u which is what ahs happened... i think i'm wrtiing jibberish..hope it makes sense :)
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They're both the same, just need to sub in the values correctly. The two just swap where the a and b are
for example, if you find the least squares regression using the y=ax + b template from the menu, then you need to use the a value it gives you for a and the b value for b. similarly, if you use the y=a + bx, the value it gives you must be used for the a and b!
And you'll notice, they just switch the a and b, try it out! find the equation for the same set of data, using both ways.
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They're both the same, just need to sub in the values correctly. The two just swap where the a and b are
for example, if you find the least squares regression using the y=ax + b template from the menu, then you need to use the a value it gives you for a and the b value for b. similarly, if you use the y=a + bx, the value it gives you must be used for the a and b!
And you'll notice, they just switch the a and b, try it out! find the equation for the same set of data, using both ways.
I think thats what I tried yesterday.
But doesnt y=ax+b give a different answer to y=a+bx? Oh wait. Is B the intercept for the y=a+bx equation? and A is the slope? That would answer errthing.
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The co-efficient of x is the slope, and the extra constant is the intercept
So for a y=a+bx eqn, b is the slope and a is the intercept :)
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So a is the slope and b is the intercept in the y=ax+b equation?
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So a is the slope and b is the intercept in the y=ax+b equation?
Correct
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they are the same... i would use whichever one the cursor would land on haha!