+0  
 
0
190
2
avatar

Question: Show that all line through the points A (p, p +1) and B (2p, p +2) with p ≠ 0 cross the negative x-axis

How do I have to do this?

Guest Aug 20, 2015

Best Answer 

 #2
avatar
+5

Thanks!

 

Guest Aug 20, 2015
Sort: 

2+0 Answers

 #1
avatar+90988 
+5

A (p, p +1) and B (2p, p +2)

$$\\gradient=\frac{p+2-p-1}{2p-p}\\\\
gradient=\frac{1}{p}\\\\
y=\frac{x}{p}+b\\\\
Sub\;in\;point\;A\\\\
p+1=\frac{p}{p}+b\\\\
p+1=1+b\\\\
so\;b=p\\\\
$Equation of line is $ y=\frac{x}{p}+p\\\\$$

 

If p is negative the the y intercept is negative and the gradient is negative so it will cut the negative x axis.

If p is positive the the y intercept is positive and the gradient is positive so it will cut the negative x axis.

Melody  Aug 20, 2015
 #2
avatar
+5
Best Answer

Thanks!

 

Guest Aug 20, 2015

12 Online Users

avatar
avatar
avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details