SAT Subject Test Mathematics Level 1

(Marvins-Underground-K-12) #1

Here’s a question that really requires a calculator, but not until a late
problem-solving stage:


What you have here is essentially a quadratic equation in which the unknown
is tan x. For simplicity’s sake, substitute y for tan x:


Now solve for y:


Now you know that tan x = 3 or –2. Since x is a positive acute angle, the
tangent is positive, and tan x = 3. Now’s the time to use your calculator. You
want to know what acute angle has a tangent of 3. In other words, what you’re


If  0°  <   x   <   90°,    and tan^2 x −   tanx    =   6,  which   of  the following   could   be
the value of x in degrees (rounded to the nearest degree)?

3.


(A) 63


(B) 67


(C) 72


(D) 77


(E) 81

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