Tuesday, June 23, 2015

New York State Geometry Regents, June 2015 Parts 3 and 4

Here are Parts 3 and 4 of the New York Geometry Regents (non-Common Core) exam. Part 2 was posted here.

Part 3

35. Solve the following system of equations graphically. State the coordinates of all points in the solution.

y + 4x = x2 + 5
x + y = 5
(0, 5) and (3, 2) were the solutions and they had to be stated. If you made a graphing error, then whatever points of intersection you had needed to be stated. If you graphed the system so that neither line touched, you would have needed to state that there was No Solution. Otherwise, you would have lost more points on top of your graphing error.
Note that arrows at the ends of the lines were not required. Labeling the lines wasn't required. I'm assuming because it was a Geometry test and not an Algebra test. I still recommend you do these things anyway, in case the standards change again.


Two points for x and y, with work. Three points if you got as far as 18 and 34, or if you came up with 52 (without solving 18 and 34 separately). With all those calculations, many students lost a point for a computation error, such as -1 + 15 = 16.

37. Point P is 5 units from line j. Sketch the locus of points that are 3 units from line j and also sketch the locus of points that are 8 units from P. Label with an X all points that satisfy both conditions.

The circle will touch the bottom line in only one place because the 5 + 3 = 8. (The addition wasn't required, but it's a good reference for yourself while sketching.)
Note that it didn't have to look pretty. In a "sketch", you don't need to measure with a ruler or draw a circle with a compass. (Neither of which I had on hand, obviously.)

Part 4

Part 4 was worth 6 credits. Please don't ask me individual questions about your proof. This is A proof. Yours might've looked similar or not. It might've had more statements. It might have skipped a statement. As long as the important stuff is there, you did okay. Looking at the sample proofs given, this one would have received full credit.


There are many possible variations, which is why I try not to grade the proofs if I don't have to. I would go insane applying Regents rubrics/grades to them.

How'd everyone do?


Anonymous said...

I didn't write the addition postulate for the proof :( I forgot the name, so i just explained that if you add two congruent line segments to the same line segment, the two line segments will still be congruent. How many points off do you think that is?

Anonymous said...

I drew a locus where it said it was 5 units away from the line so I got 4 X's. How much points do you think I would lose?

(x, why?) said...

Anonymous 1: If you explained it, you might not have lost anything as long as the statement and the reason where there (and correct). Maximum, it's a one-point deduction. With luck, 0 points lost.

Anonymous 2: Away from the line wouldn't be a circle, so it's likely a conceptual error, and that would be half of the credits.

Anonymous said...

What is the curve for the common core geometry?

Anonymous said...

For question #35, if I didn't state the coordinates of intersection but still graphed and labeled everything correctly, how many points will I lose?

(x, why?) said...

Re the curve: I don't have the conversion charts. For CC Geometry, I don't think one has been released yet.

Re #35: If you graphed the lines correctly, but didn't state the solution (the points of intersection), you lost 2 points. That was a conceptual error, half credit.

Anonymous said...

What if I didn't label the loci? I drew the X's correctly, but I didn't write the units away from each line.

(x, why?) said...

You probably got your score already, but you didn't need to label anything, except the X's.

Everything else I wrote is pretty much for explanation purposes, but not needed -- in case someone didn't realize that the second line would be tangent to the circle, for example.

Unknown said...

I believe that will still be full credit. One example of th addition postulate is that:

When a segment (or congruent segments) is added to congruent segments, the sums are congruent.