Mathematics Level IC/IIC Subject Tests
245
ARCO
■
SAT II Subject Tests
w w w . p e t e r s o n s . c o m / a r c o
42. The correct answer is (C). [–] The general form of the equation of a circle is:
(
x –
h)
2
+ (
y –
k)
2
=
r
2
where (
h,
k) is
the center of the circle and r its radius. The circle described in the question stem has a
radius of 2 and its center at (2, –1):
If
a line of the form x =
k (a vertical line) is tangent to this circle, it passes through point (0, –1) or (4, –1).
43. The correct answer is (D). [0] The
graph intersects the y–axis where
x = 0:
y = 2 cos 2(0) + 2
y = 2 cos 0 + 2
Since cos 0 = 1:
y = 2(1) + 2 = 4
44. The correct answer is (D). [–] According to the Binomial Theorem, the
last term in the expansion
of a binomial having the form (
a +
b)
n
is
b
n
. So the last term of this expansion will be (3
y)
4
= 81
y
4
.
45. The correct answer is (C). [–] Since a die has six faces, the chance that any
one of those faces will be
exposed is 1 out of 6. With two dice, the chance that any two faces will both be exposed is 1/6
× 1/6 = 1/36.
There are, however, three combinations that total 4: 1 + 3, 2 + 2, and 3 + 1. Thus, the chance that a 4 will
appear is 3/36 = 1/12.
Do'stlaringiz bilan baham: