Answer:
- y-intercept: y=9
- zeros: x= -3, -1, 1, 3
Explanation:
The y-intercept is where the graph crosses the y-axis. On this graph, that is just below y=10. A reasonable estimate* of the y-intercept is y=9.
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The zeros are those places on the graph where y=0. The line y=0 is the x-axis, so the zeros are the x-values of the places where the graph crosses the x-axis. Those points are clearly labeled: x = -3, -1, 1, 3.
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* Knowing the zeros, you can write a factored-form equation for the graph:
y = (x +3)(x +1)(x -1)(x -3)
You can substitute x=0 in this equation to see what the y-intercept would be:
3×1×-1×-3 = 9
That is, with no scale factor applied to the function, its y-intercept would be 9. This is the same value we estimated above, so it is reasonable to assume that value is correct.