Rocko911 wrote:
Carcass wrote:
\(y= 2x^2 + 7x - 3\)
Quantity A |
Quantity B |
\(x\) |
\(y\) |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Practice Questions
Question: 5
Page: 112
Difficulty: medium
Do we take out the roots of X only when the equation is equal to 0 rather than y?
A lot of students will automatically want to take \(y= 2x^2 + 7x - 3\) and convert it to the equation \(0= 2x^2 + 7x - 3\), however, we've now removed an entire variable (y) from the equation, which makes no sense.
Here's an analogous example: If we have the equation y = x - 2, there are infinitely-many solutions including, x = 0 & y = -2, and x = 2 & y = 0, and x = 5 & y = 3, and x = 10 & y = 8, and . . .
If we magically turn the y into a 0, we get: 0 = x - 2, which means x = 2 (what about y?)
As you can see, turning the equation \(y= 2x^2 + 7x - 3\) into the equation \(0= 2x^2 + 7x - 3\) creates a totally different equation.
Cheers,
Brent
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Brent Hanneson – Creator of greenlighttestprep.com
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