Double Angle Identities & Formulas of Sin, Cos & Tan - Trigonometry

CBS News on Instagram: "Video shows the suspected attacker who attacked crowds in Taipei, Taiwan, with a knife and smoke grenades, killing at least three people and injuring nine others. The suspect later fell to his death from a department store building. The suspect, identified as a 27-year-old man named Chang Wen, threw a smoke grenade near an underground exit of the Taipei Main subway station, close to the city's main train station, sending pedestrians running, according to local media repor