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how do you find the y intercept

How do I find out how to find the y intercept

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David S. | Wise Math TutorWise Math Tutor
5.0 5.0 (58 lesson ratings) (58)

The y intercept on a graphed equation is where the graphed equation crosses the y axis. x would equal zero at this spot. In a linear equation such as y = mx +b where m is the slope, b is the y intercept. Lets look at the equation y= 3x + 7 the slope is 3 and the y intercept is 7 So if they give you any linear equation put it in the form of y = mx +b first and your b will be the y intercept. Example 3y -x =15. I change this to 3y = x + 15 by adding x to each side. Now I change this to y = 1/3x +5 by dividing each side by 3. The slope of the original equation is 1/3 and the y intercept is 5.

Sandeep S. | Sandeep - Your Math TutorSandeep - Your Math Tutor
Find the y-intercept by putting x=0
Brad M. | STEM Specialist plus Business, Accounting, Investment & EditingSTEM Specialist plus Business, Accountin...
4.9 4.9 (229 lesson ratings) (229)
Hey Harvey -- lines cut the y-axis when x=0 ... for f(x), look at f(0) ... Regards, sir :)
Beth L. | Patient, Knowledgeable and Very Qualified Mathematics TutorPatient, Knowledgeable and Very Qualifie...
y-intercept is where the line, parabola, etc. crosses the y axis.  In order to find it, let x=0.  Then you will have y = a number. 
One way to find the graph of a function is to try putting 0 is for x (y intercept) and then put 0 in for y (x intercept).  That will give you two points to work with.  If it's a line, connect the two points.  If it's a parabola (contains x2 you will know the approximate shape of it.  Anything higher than x2, such as x4 or x7, use a graphing calculator or computer math program such as MathWorks.  Find one that offers a 3D perspective that you can tilt, compare different equations (such as y=x2 and y = 2x2).  Ask your math teacher or the math department head at a local college which computer program they would recommend.  It helps a great deal in understanding the graphs of the higher powers of x if you can see them on a computer screen.