# Welcome to Planet Infinity KHMS

## 31 January, 2010

### Question Bank -Mathematics Class X by DOE

Dear students,
You may practice questions from the following resource issued by DOE.

## 27 January, 2010

### CBSE Sample Papers

Given below is the list of useful Sample papers for Class X Mathematics.
1. Sample Papers issued by C.B.S.E.
2. Question Paper - Delhi 2009

## 26 January, 2010

### #5 Math error: Splitting the middle term

When factorising a quadratic polynomial by splitting the middle term method,observe the sign of middle term to be splitted. Look into the following mistakes.

-3x is not equal to 6x-3x. Observe -3x is not equal to -3x-6x. Try to avoid these kinds of mistakes. Be careful.

## 15 January, 2010

### #4 Math error discussion (Avoid calculation errors)

What is 65x2+45 ? Is it equal to117?
Is it possible ?

BODMAS rule is important.

What is 13-7?
What is 4+64?

What is 9 +25?

## 07 January, 2010

### #3 Math error discussion (Math formulae)

Remembering correct Math formulae is important. In Mathematics most of the content learning is formulae based. At the time of examination if the formula used is not correct then there is no point wasting time in doing calculations and obtaining absurd results. Learning Math formulae and then remembering is a difficult task for many learners. I know there are n number of formulae with so many terms having different meaning. Its a challenging task to remember them . But you see, there is no escape . You have to remember them and apply them correctly for solving the given problem.
Some tips for learning Math formulae.

1. Do not just cram formulae. Meaning of each term is significant and helpful in memorising.
2. Try to learn them by writing.
3. Understanding of formulae is important. At times conditions are given with the formula. Learn the significance of the given condition and remember it.
4. You may make a list of important formulae and stick it on the wall opposite to your study table. It helps!
5. No matter you have learnt the formule or you know them very well, keep revising . Revision makes the brain perfect. You will get the correct reply at the time of examination.
6. Make a handy notebook of formulae and important basic concepts. When you find some free time in school, may be in an arrangement period, read and write the formulae.
7. You may experiment by associating a story , a connection , or anything which you remember with a difficult formula as a signal for remembering . Sometimes it proves beneficial.
8. If you forget formulae , it means you can learn it again by practicing. All you need is to focus a little more. Concentrate on your work.

See what happen when you do not know the correct formulae...

## 06 January, 2010

### #2 Math error discussion: About question on construction

Construct a triangle of sides 4 cm, 5cm, and 6 cm and then a triangle similar to it whose sides are 3/2 of the corresponding sides of the first triangle.

Most of the students made the right construction but they have not written given, required and result. Please write in the end which part is the required constuction.

When steps of construction are not asked then do not waste your time in writing steps of construction. You would not be getting extra marks for writing the same.
Some of the students have constructed a triangle similar to the given triangle having sides 2/3 of the sides of given triangle. Please Read the given scale factor and attempt the question accordingly.

## 05 January, 2010

### General points to remember for Math Exam

1. Pls do not spend much time in showing steps of calculation in 1 mark questions. Only the final answer is important. No 1/2 mark is awarded in such questions.
2. In 2 marks questions, specify reason wherever required.
3. In the question based on construction, pls write given , required and result. Write steps when asked.
4. In question on graphs, label axes, do whatever is asked.
5. In question on heights and distances, draw diagram and explain it. Write formula wherever required.
6. In question on probability, do write formula.
7. Attempt questions of each section at one place. You may start with any section .

## 03 January, 2010

### #1 Math error discussion

The following ways of solving trigonometric expressions are not correct. Correct solution of solving it is given in the end.
(Trigonometry is not solved like algebra rules.)

The correct way of solving the given expression is
Use formulae of T-Ratios of complementary angles.

## 01 January, 2010

### Happy New Year

Dear students,

Happy New Year 2010.
All the Best for your exams!