SAT Subject Test Mathematics Level 2

9 . D

Use the distance    formula to  calculate   the lengths between each    pair    of  points. The

perimeter   of  the triangle    is  the sum of  these   lengths.

10 . E

g(f(x)) is  a   compound    function.   Since   f(x)    =   x   +   4,  g(f(x)) =   6   –   (x  +   4)^2

Once    you have    figured out the compound    function,   you answer  this    question    with    the help

of  a   graphing    calculator, which   will    indicate    the highest point   of  the graph.

Alternatively,  you can find    the maximum of  the function    by  first   finding the minimum value

of  the squared binomial.   (x  +   4)^2    has a   minimum value   of  zero,   since   a   square  never   has a

value   less    than    0.  Six minus   0   equals  6,  and that    is  the maximum value   of  the function    g(f(x)),

which   occurs  when    x   =   −4. For any value   of  x   other   than    −4, (x  +   4)^2    will    be  greater than    0,  so

the function    will    have    a   value   less    than    6.

11 . C