x-intercept of a line (video) | Khan Academy (2024)

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  • retrest

    6 years agoPosted 6 years ago. Direct link to retrest's post “How do you find the y int...”

    How do you find the y intercept?

    (20 votes)

    • michael Li

      6 years agoPosted 6 years ago. Direct link to michael Li's post “You can take the function...”

      x-intercept of a line (video) | Khan Academy (4)

      x-intercept of a line (video) | Khan Academy (5)

      You can take the function f(x) = something (your funtion) so like f(x)=2x. you can input x=0 and find the output which would be the y intercept. So, lets actually have f(x) = 5x + 2. You input 0 for x and you get f(x) = 2. That is your y intercept

      (27 votes)

  • Ani-Jay

    7 years agoPosted 7 years ago. Direct link to Ani-Jay's post “How do you know where to ...”

    How do you know where to put your intercepts when answering the problems.? I haven't been able to get 100% on the practice problems, because my answers need to be reversed, but I can't figure out where to place them.

    (11 votes)

    • bgale28

      9 months agoPosted 9 months ago. Direct link to bgale28's post “in slope-intercept form, ...”

      in slope-intercept form, ( y=mx+b ) b represents your y-intercept.

      (5 votes)

  • AshwathMalaisamy

    11 years agoPosted 11 years ago. Direct link to AshwathMalaisamy's post “for example how would you...”

    for example how would you find the x intercept for a problem like this ?Y = x2 + 5x + 4
    y = x squared plus five x plus four

    (5 votes)

    • Rachel

      11 years agoPosted 11 years ago. Direct link to Rachel's post “It's a quadratic equation...”

      x-intercept of a line (video) | Khan Academy (12)

      It's a quadratic equation, which means it's a non-linear (is parabolic in shape). You can find the x-intercepts (usually there are 2, but there can be 1 or none) by completing the square, factoring or by using the quadratic formula. Which method I use depends on which one I think will make solving the problem easier. The easiest way to solve is to factor the quadratic equation.
      x^2+5x+4=0

      We set it equal to zero because we are looking for the x intercepts.
      When y is 0 where will the parabola cross the x-axis

      To solve by factoring we ask ourselves: What two numbers add up to the middle term and are the product of the last term?
      4*1=4 (last term)
      4+1=5 (middle term)
      (x+4) (x+1)
      set them both equal to zero to find the x intercept
      x+4=0
      subtract 4 from both sides
      x=-4
      x+1=0
      subtract 1 from both sides
      x=-1
      x intercepts are -4 and -1. Or the points where the parabola crosses the x-axis are (-4,0) and (-1,0).

      (10 votes)

  • Sara Beth

    8 years agoPosted 8 years ago. Direct link to Sara Beth's post “Can't you find the interc...”

    Can't you find the intercept by doing -b/2a, or is that finding the vertex?

    (5 votes)

    • KathyC

      8 years agoPosted 8 years ago. Direct link to KathyC's post “A vertex is a corner, whe...”

      A vertex is a corner, where two lines meet. A straight line by itself doesn't have a vertex.

      The easiest way to find the x intercept is to figure out what value x will have when y = 0.
      So if you have an equation of a line: 2y + 4x = 28
      you substitue "0" in for your y and solve:
      2 (0) + 4x = 28
      4x = 28
      x = 7
      The x intercept is (7,0)

      (7 votes)

  • poodoo

    a year agoPosted a year ago. Direct link to poodoo's post “at 0:48 where did 0 come ...”

    at

    x-intercept of a line (video) | Khan Academy (17) 0:48

    where did 0 come from?

    (6 votes)

    • Venkata

      a year agoPosted a year ago. Direct link to Venkata's post “We need to find the x int...”

      We need to find the x intercept. So, as it is a point on the x axis, the y coordinate has to be 0. So, we substitute y = 0 into the equation.

      (3 votes)

  • daP0l15hc0unt

    6 years agoPosted 6 years ago. Direct link to daP0l15hc0unt's post “Slope intercept form is y...”

    Slope intercept form is y=mx+b.
    Is there a way to use the x-intercept instead of the y-intercept. Use p for the y-intercept in your equation.

    My attempt:
    y = mx + b
    0 = mx + b
    0 = x + b/m
    x = -b/m
    let p be the x-intercept
    therefore: p = -b/m
    Therefore:y = mx - mp
    Am I right?

    (4 votes)

    • KoJesko

      6 years agoPosted 6 years ago. Direct link to KoJesko's post “If m = 3 and b = 2 (Subst...”

      If m = 3 and b = 2 (Substitute) 0 = 3x + 2 (0 = mx + b) (Subtract b from both sides)
      0-2 = 3x (y-b = mx) -2 = 3x (y-b = mx) (divide both sides by the amount x is multiplied by) -2/3 = x

      (4 votes)

  • Ammon Trump

    7 years agoPosted 7 years ago. Direct link to Ammon Trump's post “How would I find the x an...”

    How would I find the x and y intercepts and graph them if I have a function 3x - 5y=15

    (6 votes)

    • edenbercier

      6 years agoPosted 6 years ago. Direct link to edenbercier's post “I'm confused at how he go...”

      I'm confused at how he got 7/3 is equal to 6/3 + 1/3 ?

      (1 vote)

  • rreid

    8 months agoPosted 8 months ago. Direct link to rreid's post “i understood nothing in t...”

    i understood nothing in the video

    (5 votes)

    • Angelina

      3 months agoPosted 3 months ago. Direct link to Angelina's post “I can explain!The x-int...”

      I can explain!

      The x-intercept of a line is the point at which the line crosses the x-axis.

      In other words, it’s the value of x when y equals zero in the equation of the line.

      For a line represented by the equation y=mx+b,
      where m is the slope and b is the y-intercept, the x-intercept can be found by setting y to zero and solving for x.

      So, if we set y to zero, we get:

      0=mx+b

      Solving for x gives us:

      x=−b/m

      This value of x is the x-intercept of the line. It represents the point on the x-axis where the line intersects. If the line never crosses the x-axis, then it has no x-intercept.

      For example, the line

      y=2x+3

      has an x-intercept at x=−3/2
      or x=−1.5.

      This means the line crosses the x-axis at the point (-1.5, 0).

      I hope this explanation helps! Let me know if you have any other questions.

      (0 votes)

  • 🥳 Arielle the amazing person

    6 months agoPosted 6 months ago. Direct link to 🥳 Arielle the amazing person's post “i have no idea what this ...”

    i have no idea what this is, and i cant belive that i have to do school work on marten luthar king jr. day.😭

    (4 votes)

  • liohara

    5 months agoPosted 5 months ago. Direct link to liohara's post “anything times zero is ze...”

    anything times zero is zero right? im so tired right now

    (2 votes)

    • Taders09

      5 months agoPosted 5 months ago. Direct link to Taders09's post “that's, right anything ti...”

      that's, right anything times zero is zero.

      (5 votes)

x-intercept of a line (video) | Khan Academy (2024)

FAQs

How to find the x-intercept of an equation Khan Academy? ›

Any point that is on the x-axis will have a y-value of 0. So, you find the x-intercept by using y=0 in the equation and solve for X. You will then have a point (x-value, 0) that is the x-intercept.

What is the x intercept of the line 18x 5y 12? ›

To find the x-intercept of the line 18x - 5y = 12, we set y = 0 and solve for x. 18x - 5(0) = 12 18x = 12 x = 12/18 x = 2/3 So, the x-intercept of the line is (2/3, 0).

How to find the x-intercept of a line? ›

For a line represented by the equation y=mx+b, where m is the slope and b is the y-intercept, the x-intercept can be found by setting y to zero and solving for x. This value of x is the x-intercept of the line.

What is the x-intercept of a line passing through 1/4 and 4:1? ›

=>x=5. What is the x-intercept of the line passing through (1, 4) and (4, 1)?

How do you solve for the x intercept method? ›

To find the x-intercept, set y=0 and solve for x. To find the y-intercept, set x=0 and solve for y. This method of finding x- and y-intercepts will be used throughout our study of algebra because it works for any equation. To graph a line, find the intercepts, if they exist, and draw a straight line through them.

What is the x intercept of the line calculator? ›

What is Meant by the X-Intercept? In mathematics, the x-intercept is defined as a point where y=0. To find the value of the x-intercept for the given straight line equation, substitute y=0 in the straight-line equation Ax+By= C.

What is the x-intercept of the line 5x + 11y = 2? ›

To find the x-intercept of the line 5x + 11y = -2, we set y = 0 and solve for x. When y = 0, the equation becomes 5x + 11(0) = -2. Simplifying gives us 5x = -2, and dividing both sides by 5, we find that x = -2/5. So, the x-intercept of the line is x = -2/5.

What is the x intercept of the line 6x 4y 14? ›

Explanation: To find the x-intercept of the line 6x - 4y = 14, we need to set y = 0 and solve for x. So, the x-intercept is (7/3, 0).

How to find x-intercept on a graph without an equation? ›

Using a Graph of a Line

It is important to look at the x-axis when locating the x-intercept. Find the point where the line crosses the x-axis. The x-intercept is this point. If you are asked to find the x-intercept based on the graph, the point will likely be exact (for example, at point 4).

Is x-intercept the same as slope? ›

Slope (aka rise over run, gradient) measures how fast y changes with respect to x. Think “steepness.” An x-intercept is a point where the graph touches the x axis. A y-intercept is a point where the graph touches the y axis.

How to average x-intercepts? ›

We know we can find the x-intercepts of the parabola by using the quadratic formula. The x-value of the vertex is located midway between these 2 points. If you average the two x-intercepts, you get their midpoint. This means you add the 2 points then divide by 2.

How do you find the x intercept fast? ›

To find the x-intercept we set y = 0 and solve the equation for x. This is because when y=0 the line crosses the x-axis. When an equation is not in y = mx + b form, we can solve for the intercepts by plugging in 0 as needed and solving for the remaining variable.

How to find x from a linear equation? ›

In order to solve the given equation, we bring the numbers on the right-hand side of the equation and we keep the variable on the left-hand side. This means, 3x = 18 - 6. Then, as we solve for x, we get, 3x = 12. Finally, the value of x = 12/3 = 4.

How do you show no x intercept? ›

So, to answer your question, any equation of the form y=b will have no x-intercept, except y=0, which will have infinitely many intercepts. The same can be true of lines that have no y-intercept, but their slope is undefined and you can graph them with the formula x=b instead.

What is the formula for the x intercept function? ›

Here, y = mx + b is the slope-intercept form that can be used to identify the x and y-intercepts. The x-intercept is found by setting y = 0. On substituting the value of y =0, it gives the x-intercept value at which the line crosses the x-axis.

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