ADB is a right angle is because central angle ACB is 180° and ADB is an inscribed angle whose endpoints are the same as ACB.
ADB = 1/2(ACB)
ADB = 1/2(180) = 90
For the above to hold true: (1) C must be the center of the circle (2) AB must be a diameter of the center
Find two numbers whose sum is b (or 2 in this example) and whose product is c (or -8 in this example).
Two such numbers are -2 and + 4, which add to +2 and multiply to -8.
a2 - 2ab + b2
"StudyBlue is great for studying. I love the study guides, flashcards and quizzes. So extremely helpful for all of my classes!"Alice , Arizona State University
"I'm a student using StudyBlue, and I can 100% say that it helps me so much. Study materials for almost every subject in school are available in StudyBlue. It is so helpful for my education!"Tim , University of Florida
"StudyBlue provides way more features than other studying apps, and thus allows me to learn very quickly! I actually feel much more comfortable taking my exams after I study with this app. It's amazing!"Jennifer , Rutgers University
"I love flashcards but carrying around physical flashcards is cumbersome and simply outdated. StudyBlue is exactly what I was looking for!"Justin , LSU