Which of the following are identities? Check all that apply. A. cos(x+y)+cos(x-y)=cos^2x-sin^2y
B. sin(x-pi)=-sinx
C. sin(x+y)-sin(x-y)=2cosx siny
D. cos(x+y)+cos(x-y)=2cosx cosy

Which quadratic function best fits this data? x y 1 32 2 78 3 178 4 326 5 390 6 337 a. y=11.41x2+154.42x−143.9 b. y=−11.41x2+154.42x−143.9 c. y=11.41x2+154.42x+143.9 d. y=−11.41x2+154.42x+143.9

Which inequality statement describes the two numbers on a number line? "? 7 and a number 5 units to the right of ? 7"

Which best describes the construction of a triangle if given the segment lengths of 2 cm, 3 cm, and 5 cm? a) unique triangle b) cannot be determined c) triangle not possible d) more than one triangle