SAT Subject Test Mathematics Level 2

x   =    x  +   1

With    this    you can express the definition  of  the function:

f(x)    =x  +   x

=x  +   ( x     +   1)

= 2 x   +   1

20 . C

21 . B

To  be  in  the domain  of  this    function,   x   must    not be  anything    that    makes   the expression

under   the radical negative    or  that    makes   the denominator zero.   The expression  under   the

radical is  x   −   1,  and it  must    be  nonnegative:

The denominator’s   simply  x,  which   then    cannot  be  zero.   It’s    already been    established,

however,    that    x   must    be  greater than    or  equal   to  1,  so  that’s  the domain.

22 . B
There is a formula that applies to this situation. The number of distinct permutations of n
things, a of which are indistinguishable, b of which are indistinguishable, etc., is

Here    there   are 6   chairs, 2   of  which   are indistinguishable   and 4   of  which   are indistinguishable,

so  the number  of  permutations    is