What is the x intercept od this piecewise function? a) (0,2) b) (2,0) c) (0,4) d) (4,0)

Choice B) (2,0)

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Set the first piece equal to zero and solve for x

x^2 - 4 = 0

x^2 = 4

x = sqrt(4) or x = -sqrt(4)

x = 2 or x = -2

Keep in mind that the first piece y = x^2-4 is only graphed when x = 2 or larger, so we ignore x = -2. This is one x intercept, but there may be more. Let's check the other graph to see what we get.

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Set the second piece equal to zero and solve for x

x-2 = 0

x-2+2 = 0+2

x = 2

We get the same result as above in the prior section. Because of this, the two pieces connect at this junction point.

The x intercept x = 2 leads to the location (2,0). The x intercept always occurs when y = 0.

The graph below shows this.

side note: the red piece y = x^2 - 4 looks linear, but it's actually not a straight line. It's just a really stretched out curve.

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!