Yes! When the question asks for the "positive difference" between two numbers, it is effectively asking for the absolute value of the difference between them. The formula for the positive difference between two values a and b is: Positive difference = |a-b| =) =)
For the parabola question 15:30, it is generally more efficient to use the vertex form. a (x - 2)^2 + k ax^2 - 4ax + 4a + k From which we get b = -4a (a+b) = a - 4a = - 3a If a is an integer greater than one, (a+b) could be -6, -9, -12, etc
You're absolutely right! Using the vertex form is a very efficient way to approach this problem, and you correctly identified that a+b=−3a, leading to possible values like -6, -9, and -12 for a>1. It's great to see such a solid understanding of different methods to solve the problem. The method I used, expanding from the factored form, is another valid approach that directly ties the solution to the roots of the equation. Both methods are valuable tools in solving quadratic problems, and it's always helpful to be familiar with multiple approaches. Amazing work! Thank you for your comment =)
Hello! We have put the simplest ways in this video. This video, in particular, is full of the most challenging questions that you could potentially encounter on the exam and for many of those there is not a simple and fast shortcut. It is imperative to know the concept behind the question and what is being tested, so that you can recognize it and apply it if you see it on your exam. =) ....We are releasing "quick math hacks" video this week, so be sure to check out that! Thanks for you support. =)
