Home->ACT Math

What is cos given that = + and that cos (a+b) = cos a (cos b) - sin a (sin b)? (Note: You may use the following table of values.)

(A)

(B) -

(C)

(D) 0.999

(E)

In the figure below, ray was constructed starting from rays and . By using a compass D and G were marked equidistant from E on rays  and . The compass was then used to locate a point F, distinct from E, so that F is equidistant from D and G. For all constructions defined by the above steps, the measures of ∠DEF and ∠GEF:

(A)are equal. (B)are NOT equal. (C)sum to 30°. (D)sum to 45°. (E)sum to 60°.

Correct Answer: C

The amplitude of the trigonometric function shown below is defined as the average of the absolute values of the maximum value of f(x) and the minimum value of f(x). The trigonometric function graphed below can be described by the equation f(x) = a sin(bx + c), where a, b, and c are real numbers. Which of the following values describes the amplitude of this function?

(A) 1 (B) 2 (C) 3 (D) π (E) 2π

Correct Answer: C

Which of the following is a possible value of xif 5x2– 10x+ 4 = 0?

(F) (G) (H) (J) (K)

Correct Answer: H