Farina wrote:
huda wrote:
OFFICIAL EXPLANATION:
Statement I tells you directly that b, the y-intercept, is equal to 0. Thus, the line passes through the origin.
For statement II, both the slope and the y-intercept could be 0, in which case line z is a horizontal line lying on the x-axis and therefore passes through the origin. Or, the slope and y-intercept could simply be opposites, such as 2 and -2. A line with a y-intercept of -2 and a slope of 2 would not pass through the origin. Therefore, this statement is not sufficient to determine whether line z passes through the origin.
As for statement III, since |a| = |b| must hold for every point on the line, then (0, 0) is a point on the line, since |0| = |0|.
For statement 3, why did you consider |a| and |b| = 0?
Key concept: If a point lies ON a line, then the coordinates of that point must SATISFY the equation of that line.Statement 3: For any point (a, b) on line z, |a| = |b|This tells us that all points on the line are such that the absolute value of the x-coordinate = the absolute value of the y-coordinate.
In other words, |x| = |y|
So, for example, since |-3| = 3, we know that the point (-3, 3) lies on line z
Likewise, since |0| = 0, we know that the point (0, 0) lies on line z
In other words, line z passes through the origin
Cheers,
Brent