Which of the following best explains why cosine StartFraction 2 pi Over 3 EndFraction not-equals cosine StartFraction 5 pi Over 3 EndFraction?

A ) The angles do not have the same reference angle.
B) Cosine is negative in the second quadrant and positive in the fourth quadrant.
C) Cosine is positive in the second quadrant and negative in the fourth quadrant.
D) The angles do not have the same reference angle or the same sign.

true

step-by-step explanation:

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8

solve systems of equations by graphing. a system of linear equations contains two or more equations e.g. y=0.5x+2 and y=x-2. the solution of such a system is the ordered pair that is a solution to both equations. to solve a system of linear equations graphically we graph both equations in the same coordinate system

i'm not really sure how to answer that

step-by-step explanation: