how to find the y-intercept (1 Viewer)

[Crizzy]

This is from the Excel general maths book (p93, question 42).
Anyway the question is find the equation of the line of best fit from example 43. (which is a graph)

The gradient is 6/7, which i understand, but the y-intercept is 7, and i don't know how they got 7.

Is it just by looking at the graph is seeing where is cuts the y axis or is there a formula where i can use to sub in the gradient to find the y-intercept?



:burn: :burn:

 

[watatank]

what's the whole question?

yeah y intercept is where a function cuts the y axis. you can find it if you have an equation in the form ax + by + c = 0 and you make x = 0 and solve for y and get the y intercept.

 

[Crizzy]

what's the whole question?

yeah y intercept is where a function cuts the y axis. you can find it if you have an equation in the form ax + by + c = 0 and you make x = 0.

sorry but i dont get you. That is the whole question. "Find the equation of the line of best fit in example 43.

Example 43 is a graph and its easy to see the gradient but i dont know the y-intercept.

 

[watatank]

i don't have the book in front of me so i got no idea.

yeah if you're just looking at a graph then the y intercept is where the function cuts the y axis, as i have said. which you can see immediately, easier to find than the gradient since that is rise/run.

 

[Kiim2507]

Once you find the equation of the line you let x= o
I think lol

 

[Crizzy]

ok i think i get it now, thanks.

 

[freakyzu]

the y- intercept is, in the equation, the single number : y = mx + b
b is the y-intecept

 

[Jonny90]

Oh shit u really wanna noe???!! well if u wanna find Y, say the alphabet out loud and u will come across the letter Y, F*ck u r stupid..... its between x and z but seriously to find Y-intercept u must intercept the ball from X and smack the f*ck out of Z and score the try under the palm tree

y = mx + b therfore z = i f*cked you up.

Hope this helps.... Peace