单选题 In the figure above, if the area of square ABCD is 64, what is the area of equilateral triangle BEC?
8
32
单选题 If tan 10° = cotθ, then θ= ______.
10°
80°
70°
-10°
90°
单选题 (6sin x) (3sin x)-(9cos x) (-2cos x) = ______.
1
-18
18
-1
18sin2x-18cos2x
单选题 If cos (45 + 2x)° = sin (3x)°, then x = ______.
18°
27 °
45°
22.5°
9°
单选题 Given the three points A(1, 2), B(6, 2), and C(6, 5), what is the tangent of ∠CAB?
3/5
5/3
3/4
1/2
单选题 In the following figure, which of the following must be true? I. cot x = 3/4 II. cos x = sin y III. tan x = tan y
I only
II only
II and III only
I and II only
I, II, and III
单选题 ______.
-1
sin 3θ cos 3θ
sin 9θ + cos 9θ
1
sec 3θ
单选题 If the area of an isosceles right triangle is 8, what is the perimeter of the triangle?
10
单选题 What is the slope of the line that is perpendicular to the line whose equation is 2x+3y=5?
-2 /3
-3/2
1/3
3/2
2/3