## Monday, April 8, 2013

### Study Material Review: SAT Subject Test Math Level 2 by Research & Education Association

I'll save you some time:  Don't buy this book.  If you need a reason you can keep reading.

This book is so full of errors it is completely useless as a prep guide.  There are only 40 pages of review (which I haven't read - they may be fine) followed by 6 practice tests with explanatory answers. The practice tests are terrible.  They are so full of errors they are useless.

Here's an example:  "A rectangle has dimensions 3, 4 and 5.  Find its diagonal."  Huh? A peek at the answers confirms that the object in question is actually a rectangular prism.

Another example:  "If SAP is the sum of the first four terms of an arithmetic progression, and if SGP is the sum of the first four terms of a geometric progression, and if the ratio of SAP to SGP is 2:3, and considering r = 2 for both of them, determine SAP + SGP."   Wow. Where to begin?  First of all, it is NEVER a good idea to assume that everyone uses the same variable name for a given unknown.  In fact, in a test question, if you wanted to give the radius of a circle, you would want to identify it as "the radius" not as "r" unless there is a diagram in which r is clearly identified as representing the radius.  This is true despite the fact that using "r" for the radius is nearly universal.

In this case however, while many typically use "r" to represent the common ratio in a geometric progression, there is no value in an arithmetic progression that would be represented with an "r" by most people.  One assumes the test author must be referring to the common difference in that equation.  However, even if we make that assumption, we cannot answer the question, because we don't know the starting value for either function.  In the answer key it is revealed that the author intended the two progressions to begin with the same value, but this is never mentioned in the question.

I have a long list of errors and I've only read through the second test.  In addition to poorly worded questions, there are stray diagrams to be found throughout the book, including a heavily annotated graph of the tangent function that appears in the answer key in the middle of an answer for a question that involves no trigonometry whatsoever.

On the cover is the disclaimer:  "SAT is a registered trademark of the College Entrance Examination Board, which does not endorse this book."  Yeah. No kidding. This book cost \$18. Not only do I not want to own it, I can't even donate it to a library.  I'm going to have to throw it in the recycling bin.  What a waste.