Urgent help!! (1 Viewer)

[umm what]

Hey Guys

Does anyone have worked solutions for topic Conics from S.K Patel??
I am stuck on some questions. There are few concepts that I don't know and therefore cannot do those type of questions.

My teacher is really slow, she started conics today, wasted half of the time writing the notes on the board. I am far ahead from class.

Thanks in advance!

 

[Carrotsticks]

Hey Guys

Does anyone have worked solutions for topic Conics from S.K Patel??
I am stuck on some questions. There are few concepts that I don't know and therefore cannot do those type of questions.

My teacher is really slow, she started conics today, wasted half of the time writing the notes on the board. I am far ahead from class.

Thanks in advance!

There are no complete worked solutions. Maybe a couple of teachers wrote their own, but nothing released (or leaked) publicly.

I don't think saying "wasted half of the time writing the notes on the board" is the appropriate term here, because you're the one ahead. She's there to teach the class as a whole, not just you.

If you have trouble with a concept, open up the textbook or another one if you must, then read through the theory for it.

Otherwise, you can ask a couple of questions here, but don't expect us to teach the whole topic for you.

 

[shongaponga]

There are no complete worked solutions. Maybe a couple of teachers wrote their own, but nothing released (or leaked) publicly.

I don't think saying "wasted half of the time writing the notes on the board" is the appropriate term here, because you're the one ahead. She's there to teach the class as a whole, not just you.

If you have trouble with a concept, open up the textbook or another one if you must, then read through the theory for it.

Otherwise, you can ask a couple of questions here, but don't expect us to teach the whole topic for you.

Agreed with Carrot. I have done practically all of the Conics excerises from Patel, so I should be able to help you out with specific questions - but definitely can not teach you the whole topic. What types of questions are you having problems with?

 

[umm what]

Exercise 6C
Questions : 16, 17

Exercise 6D
Questions: 13, 17 (c), 19


That's it I don't know the method to use in above questions, other questions are similar to the ones above.

Thanks

 

[Carrotsticks]

Exercise 6C
Questions : 16, 17

Exercise 6D
Questions: 13, 17 (c), 19


That's it I don't know the method to use in above questions, other questions are similar to the ones above.

Thanks

Could you please type out the questions? Not all of us carry around the textbook wherever we go...

 

[umm what]

Could you please type out the questions? Not all of us carry around the textbook wherever we go...

Sure in a minute

 

[umm what]

Exercise 6C
Questions : 16, 17

Exercise 6D
Questions: 13, 17 (c), 19

thanks!

 

[Carrotsticks]

Exercise 6C:

Q16: Find where the line intersects the Hyperbola by solving simultaneously. Find the equation of the tangent at that point. Show that the gradient of the tangent is perpendicular to the gradient of the line.

Q17: Differentiate implicitly and let the gradient be equal to -1 (so it's parallel to x+y=0). You should get another equation. Solve this equation simultaneously with the equation of the Hyperbola. By doing so, you have found the point of contact. Sub these points into the Cartesian Equation of the Tangent to the Hyperbola.

ALTERNATIVELY let the equation of the line be y=-x+k for some constant k (this is the general line in 2D space that is parallel to x+y=0). Solve simultaneously with the Hyperbola and let the discriminant be equal to 0 for it to be tangential. Solve for K.

Exercise 6D:

Q13: Find the equation of the general tangent at point P using the Tangent Equation formula. Solve it simultaneously with the equation:



The reason I have the absolute value sign is because there are two asymptotes:



And to denote them both in 1 expression, I use the absolute value.

Get rid of the absolute value by making it the subject then squaring both sides. Then re-arrange to make a quadratic in terms of X. Find the sum of roots and divide by 2, and show that it is the same thing as the X coordinate of P.

To find the length of AB, find the distance between either A and P, or B and P. Then multiply by 2 (because P is the midpoint).

Q17 (c): You have an expression for cos theta and sin theta. Use the Pythagorean identity sin^x + cos^x = 1 to eliminate theta, and the quadratic (actually a quartic but w/e) pops up.

Q19: Solve the line y=mx+c simultaneously with the Ellipse and re-arrange to make a quadratic. Let the discriminant be equal to 0 and the expression follows.

For the second part, we have y=mx+c. Sub in P(4,5) to get 4m+c=5.

Now we know that for the Ellipse, a^2=25 and b^2=16, so using the condition from the first part, we have:



Sub in c= 5 - 4m (we got this earlier) into this expression and we will get a quadratic in terms of M (you will have to manipulate it to make it so). Show that the Product of Roots of this quadratic is -1.

ie: m_1 x m_2 = -1

Hence the tangents are perpendicular.