# Welcome to Planet Infinity KHMS

## 11 February, 2010

### Quadratic equations-Completing the square method

This is a useful web link for learning the method of solving a quadratic equtaion by completing the square method.

## 08 February, 2010

### #6 Math error discussion (Coordinate Geometry)

A question was asked in the pre board examination from the chapter Coordinate Geometry which was the application of distance formula.

Show that the points A(1,7) , B(4,2), C(-1,-1) and D(-4,4) are the vertices of a square.

Most of the students did the following...
There are two types of errors in this solution.
First one is a calculation error, 25+9 is not 36.
The second one is a conceptual error. It is important to note that when you are asked to prove that given 4 points are vertices of a square then you need to show that AB=BC=CD=DA and lengths of both the diagonals are equal i.e. AC = BD.

Remember this!!

## 03 February, 2010

### Order of answering the paper

Recently I received many queries regarding order of answering questions in the final examination. You may start solving your paper from any Section A,B,C or D. Make sure solutions of one Section are at one place. This means if you begin from Section A then all one mark questions must be solved together at one place. Regarding 1 mark questions, Please do not waste your time in explanation. Only the final answer is required to be correctly written.
If you still have any queries pertaining to Class X Board Exam, you can write to me at mathclass_khma@yahoo.co.in