# Week 7 Video Lessons

Home Forums VMTTC Online Discussion Forum Week 7 Video Lessons

• Author
Posts
• #28847

• #32052

Hi,

This is regarding coordinate geometry, perpendicular lines.

We should interchange the coefficients and change one sign to find the equation of the line through a given point and perpendicular to the line. In that case we will have two possible answers (one positive and one negative).

For example: (-3, 4) , 5x -2y =3

Scenario 1 : 2x+5y = 14

Scenario 2 : -2x-5y = -14

Both scenarios plot the same line(same equation) extending over different quadrants.

Regards.

• #32562

Hi Mallika,

You are right that there are 2 possibilities because we can change the sign of either of the x or y coefficients. Even if we are getting two possible answers, the equation of the line remains the same because the line is extended into the two quadrants.

2x+5y+14

5y= -2x+14

y=- 2/5 x+14/5

and -2x-5y=-14

5y=-2x+14

y=-2/5 x+14/5

Thank you for pointing that out,

• #32571

Hi Savita,

There is only one line and one equation.

2x+5y=14 is exactly equivalent to -2x-5y=-14 mathematically.

One equation – one line.

• #32563

Hi mr. Ken,

Mr. James, the deputy head of math dept. in James school of London has come up with the method of finding the equation of a line passing through a given point and either parallel or perpendicular to a given line. What does it say in Shree Bharati Krishnaji’s book?

Thanks,

• #32573

Hi Savita,

Sri Bharati Krishna’s book does not mention this topic.

Mathematics is a vast subject and the book cannot cover everything. James Glover’s discovery directly relates to the Vedic Sutras and is simple and easy to understand. Hence we can include it as Vedic Maths.

• #32564

Hi Mr. Ken,

In the Vedic method for finding the equations of lines why and how do we start with the standard format of

y=mx+c?

Thanks,

• #32578

Hi Savita,

y=mx+c is a standard form for straight lines. That is because by substituting specific values for m and c the equation always plots out to a straight, and all lines are inlcuded.
The nice thing about y=mx+c is that it turns out that m is the gradient (slope) of the line, and c is the intercept on the y-axis.

Another standard form for a straight line is ax+by=c, so y=mx+c is not the only one.

• #32660

Hello,

for straight line the equation is y=mx+q or (y-yp)=m(x-xp).

For perpendicular line the equation is (y-yp)=-(1/m)(x-xp).

The angular coefficient is m in the first case and -1/m in the second case. This is the reason (video lesson 28) for the calculus to find the line who pass for P(3,1) and perpendicular to 2x+3y=5. Into this example we substitute (3,1) in 3x-2y and not in 2x+3y.

This is correct?

Thanks

• #32661

Yes that is correct Fabio.

• #33024

Ken,

The general square rooting method and finding the recurring decimals is so enlightening. Even the calculator was not showing the complete pattern for recurring decimals. Felt so nice to see that. Thank you so much Ken for sharing these methods with us.