Dr Finlay

This is a question from my school text book:-

The line y = 3x - 5 meets the x-axis at the point M. The line y = -2/3x + 2/3 meets the y axis at the point N. Find the equation of the line joining the points M and N. Write your answer in the form ax + by + c = 0.

For point M i got the coordinate (5/3, 0)

and for point N

(0, 2/3)

I next worked out the gradient of the line connecting M and N to be -2/5 and tried using y - y1 = m(x - x1) to get the equation for the line eventually getting to 6x - 15y - 3 = 0, however the book lists the answer as 6x + 15y - 10 = 0.

Is my answer the correct answer and the book's answer wrong, or did i mess up in my working out somewhere? I've been pondering on it for a while and cant see how the book got its answer.

Thanks for any help

Rob

Hello, my name is Rob. Just finished GCSEs and will be attending 6th form this year studying mathematics and physics amongst other things, although those are my favourite subjects. I also enjoy playing bass guitar, listening to music and reading (fiction such as science fiction and historical novels, and non-fiction mostly in the form of popular science).

AH! I understand that now. Thanks alot for your help. I knew it would be something simple that i missed

There are lots of slang words up here in Yorkshire. We even have our own translation of microsoft word! Northern Word

Hi,

I've just started working through volume one of Tom M Apostol's Calculus.

The first chapter gives a brief history of the method of exhaustion and attempts to show how this is used to show that the area of a parabolic segment is exactly 1/3 of the area of the rectangle enclosing it.

However when it comes to explaining equations 1.1 and 1.2, I dont understand how (n-1)^2 comes into equation 1.2.

I have attatched the parabolic segment and explanation to the problem. I know this will be some fundamental gap in my understanding of basic math but i cant follow through and understand how equations 1.1 and 1.2 differ.

Thank you in advance for any help.

parabolic segment

Explanation