Let v=(2,8) and w=(-1,-4). which of the following is true. a. v and w are perpendicular b. the x-component of v is 2 c. v= -2w d. v•w = -34

Situation: . find the substance's half-life, in days. round your answer to the nearest tenth. a 11 gram sample of a substance that's used to treat thyroid disorders has a k. value of 0.1247. enter the correct answer n - noekt done no - initial mass (at time t = 0) n - mass at timet k a positive constant that depends on the substance itself and on the units used to measure time t= time, in days