<ol>
<li>For any point on line l, the product of the x-coordinate and the y-coordinate is less than or equal to 0. Which of the following could be the equation of line l?
a.y=-2
b.x=-2
c.y=-2x
d.y=-2x-2
e.y=2x-2</li>
</ol>
<p>B, perhaps?</p>
<p>The answer is C. Essentially, you want a line that only goes through Quadrant II and Quadrant IV (because both of those consist of one negative axis values [either x or y] and the other positive values). Also, you can test by plugging in numbers, and you would find that C is the only answer that results in the multiplying of the two numbers to be equal to or less than zero.</p>
<p>ahh thanks.</p>
<p>You want something that has a negative 1st derivative, and y(0) = 0. Clearly that is choice (C).</p>