SOLUTION: Please help me answer and give some explanations as to how to solve this following question: Which of the following relations are one-to-one? Give reasons. 1. 2x - 5y =3 2. y^2

Algebra ->  Functions -> SOLUTION: Please help me answer and give some explanations as to how to solve this following question: Which of the following relations are one-to-one? Give reasons. 1. 2x - 5y =3 2. y^2      Log On


   



Question 760528: Please help me answer and give some explanations as to how to solve this following question: Which of the following relations are one-to-one? Give reasons.
1. 2x - 5y =3
2. y^2 - 3x + 7 =0
3. y= the squareroot of 5-2x
4. y= x^3 -2
5. y= x^2 - 3x +2
6. y= |3x-5|
Thank you in advance and please reply as soon as possible since i need time to learn how to arrive at the answers.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
A one to one function is a function in which every element in the range of the function corresponds with one and only one element in the domain.
Example of a one-to-one function:
{ (0,1) , (5,2), (6,4) }
Domain: 0, 5, 6
Range: 1,2, 4
Each element in the domain (0, 5, and 6) correspond with a unique element in the range. Therefore this function is a one-to-one function

If a function is one-to-one, then the function not only passes the vertical line test (the vertical line test is a way to determine whether or not a relation is a function), but it also passes the horizontal line test.
The Horizontal Line Test :
If a horizontal line only intersects with the graph of a function once, then this function is one-to-one. If a horizontal line intersects the graph of the function more than once, then this function is not one-to-one.
1. 2x+-+5y+=3
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+3%2C3%2C%282%2F5%29x-3%2F5%29+
since a horizontal line only intersects with the graph of a function once, function is one-to-one
2. y%5E2+-+3x+%2B+7+=0

since a horizontal line only intersects with the graph of a function once, function is one-to-one

3. y=+sqrt%285-2x%29

since a horizontal line only intersects with the graph of a function once, function is one-to-one
4. y=+x%5E3+-2
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+3%2C3%2Cx%5E3+-2%29+
since a horizontal line only intersects with the graph of a function once, function is one-to-one

5. y=+x%5E2+-3x+%2B2
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+3%2C3%2Cx%5E2+-3x+%2B2%29+
since a horizontal line intersects with the graph of a function twice, function is NOT one-to-one

6. y=+abs%283x-5%29
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+3%2C3%2C+abs%283x-5%29%29+
since a horizontal line intersects with the graph of a function twice, function is NOT one-to-one