Week 3 - Graded Assignment 3 - Question 8 - Solution Doubt

[Zohair Merchant]

Hi all,

The solutions mentions the following:

From the slope intercept form, the equation of the line is y = 3x + c, where c is a con-

stant.

The general form of the line is −3x + y − c = 0.

My question is why are we using slope intercept form when we are not given/ specified any of the intercept value in the question?

And even if we are using it, how can we write c is a constant, when according to the formula c is the y-intercept.

[Anand Iyer]

y = mx + c is the simplest and classy way of representing a line.  There's no other reason.

In this case m = 3

So, the equation is y = 3x + c

and, c is a y-intercept as you mentioned.  it's as a constant value in the equation, since it doesn't change its value with change in x or y.

[Debajyoti Biswas]

Thanks Anand for the right answer

[Malabika Guha Mustafi]

@ Zohair,

y=mx +c gives immediate impression how the line is placed in the cartesian coordinates ( with positive slope or negative slope). Personally , I like intercept form of the line which gives immediate two points on the line. Other thing, Anand clarified already.