Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing


Hi everyone, since two days I'm following the lesson 18.01SC and I don't really understand this: In Session 2, Clip 2 he explaines that to get the x-intercept of the triangle you have to use this formula: y - y0 = m (x - x0) with: y = 0, because it is an intercept with the x-axes. y0 = 1/x0 m = -1/x0^2 x = x x0 = x0 But I don't get why it is y - y0 and not just y0 and why it is m (x - x0)... Could someone please help me with this? If it is a bit of a stupid question, I'm sorry.

  • one year ago
  • one year ago

  • This Question is Closed
  1. jgoldsmith
    Best Response
    You've already chosen the best response.
    Medals 1

    Let's start by looking at the formula in question. M represents slope, which is defined by the rate of change of y divided by the rate of change of x, or rise over run. Since rate of change requires change over some period, you need two points: an initial point (x0 or y0), and a change point (x or y). From the definition and the statement above you get the equation \[m = \frac{ (y - y0) }{ (x - x0) }\] Multiplying both sides of the equation by (x - x0) yields the formula you are referring to, \[y-y0 = m(x-x0)\] , Which as you see follows from the original statement. Do you understand now?

    • one year ago
  2. Wiskomen
    Best Response
    You've already chosen the best response.
    Medals 0

    Hi, thanks for you question, I think I understand it now... If I find an other problem that I can't figure out, I'll be back here. Thanks you so much!

    • one year ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...


  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.