Which of the following functions has an inverse that is not a function?

a) y = x

b) y =2x + 1

c) y = x^2

Question

Which of the following functions has an inverse that is not a function?

a) y = x

b) y =2x + 1

c) y = x^2

3mar · Answer

The vertical line tests the equation if it is a function or not. The horizontal line test tells if the inverse of the function is a function or not!

3mar · Answer

for y=x
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it is a function and its inverse (the inverse is the same as the original function) is also a function!

3mar · Answer

The same for the second.

3mar · Answer

But for 
$$y=x^2$$
it is a function, but its inverse is not as there are two values of y for a single value for x.
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