Question Video: Identifying Graphs of Quadratic Equations in Standard Form | Nagwa Question Video: Identifying Graphs of Quadratic Equations in Standard Form | Nagwa

Question Video: Identifying Graphs of Quadratic Equations in Standard Form Mathematics • Second Year of Secondary School

Join Nagwa Classes

Attend live General Mathematics sessions on Nagwa Classes to learn more about this topic from an expert teacher!

Which of the following graphs represents the equation 𝑦 = 𝑥² − 5𝑥 + 8? [A] Graph a [B] Graph b [C] Graph c [D] Graph d [E] Graph e.

01:31

Video Transcript

Which of the following graphs represents the equation 𝑦 equals 𝑥 squared minus five 𝑥 plus eight?

We can make a table to come up with a few points to plug on these graphs. What is 𝑦 when 𝑥 equals zero? 𝑦 would equal zero squared minus five times zero plus eight. When 𝑥 is zero, 𝑦 equals eight. If we plug that point on all of the graphs, we see that the lines on graphs d and e do not go through the point zero, eight. Graphs d and e can’t represent this equation.

Let’s choose another value for 𝑥 to find a second point on our graph. Let’s consider when 𝑥 equals one. When 𝑥 equals one, 𝑦 equals one squared minus five times one plus eight. One minus five equals negative four. Negative four plus eight equals four. This graph should have a point at one, four.

Okay, let’s consider the point one, four. a goes through one, four. b does not go one- through one, four. And c does not go through one, four. b and c cannot graph this equation. Using a table, we’ve narrowed down the graph to a.

Join Nagwa Classes

Attend live sessions on Nagwa Classes to boost your learning with guidance and advice from an expert teacher!

  • Interactive Sessions
  • Chat & Messaging
  • Realistic Exam Questions

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy