SOLUTION: use the horizontal line test to determine which of the following are one to one functions A) y=2x^2+5x-3 B) y= [x-2] C) y=x^-1/2

Algebra ->  Functions -> SOLUTION: use the horizontal line test to determine which of the following are one to one functions A) y=2x^2+5x-3 B) y= [x-2] C) y=x^-1/2      Log On


   

Question 114811: use the horizontal line test to determine which of the following are one to one functions
A) y=2x^2+5x-3 B) y= [x-2] C) y=x^-1/2
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
If we graph y=2x%5E2%2B5x-3, we get

+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+2x%5E2%2B5x-3%29+

which fails the horizontal line test. So the function is not one-to-one

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If we graph y=abs%28x-2%29, we get

+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+abs%28x-2%29%29+

which fails the horizontal line test. So the function is not one-to-one


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Remember, y=x%5E%28-1%2F2%29 is the same as y=sqrt%28x%29

If we graph y=sqrt%28x%29, we get

+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+sqrt%28x%29%29+

which passes the horizontal line test. So the function is one-to-one