Use of Slope intercept form

[Zohair Merchant]

Hi all,

Why do we consider slope intercept form in many place even when neither x-intercept nor the y-intercept is given.

Places we've used:

1)In the lecture L3.5 (Straight Line fit).

2)In solving Week 3 Question 5 of Graded Assignment.

Why do we have to convert the given line to slope intercept form?

Why do we write "using slope intercept form"? When we don't know any of the intercept, when the question doesn't mention anything about x and y intercept values.

[Priyanshu Singh]

why do ever use slope intercept form ,and please an anyone explain in brief how to find slope inercept of an equation given to us?

[Debajyoti Biswas]

Priyanshu, Zohair,

Thanks for the nice question. The slope intercept form is actually the most widely used form of straight line as far I have seen. In SSE, you surely have used y=mx+c form. If you do any line fitting later , or use any survey data set or you want to fit a ML model somewhere, you will need y=mx+c. It is actually quite widely used, in many research fields, I have seen its usage in quantum physics, electrical engineering datasets and Chemical Engineering datasets among other places.

Answering the next question, how to find it, you obviously need the slope and you need the x-intercept or y-intercept. For finding the slope you need the two coordinates. Please check the lecture videos and solution tips. I hope it will be clear. 

[Malabika Guha Mustafi]

In brief, slope intercept form,

y=mx+c [where c is the y intercept] 

if we take x intercept,

y=m(x-d)

[where d is  the x intercept ].

All the equation of line are  actually different form of general equation,

Ax+By +C=0

slope = -A/B

c = -C/B

d= -C/A