# Mathematics

## Khan Academy's India Talent Search

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## Where do math symbols come from?

Math is full of symbols: lines, dots, arrows, English letters, Greek letters, superscripts, subscripts ... it can look like an illegible jumble. Where did all of these symbols come from? John David Walters shares the origins of mathematical symbols, and illuminates why they’re still so important in the field today.

## The Importance of Asking Questions – in Different Ways!

Most students spend a big fraction of their study time preparing themselves for answering questions – for examinations. This becomes all the more important when a student writes a competitive examination such as the IIT entrance. In such a situation, the busy student tries to consult as many question banks from as many sources as possible, ensuring that (s)he has created his/her own database with (almost) all possible variations in questions from a certain theme!

## Predicting the future

We often find ourselves needing to predict the future value of something based on past trends. For instance, climate scientists have been trying to estimate the future rise in ocean temperatures based on (among other things) temperature data of the last 100 or more years. Or maybe you are a cricket enthusiast and want to predict how many centuries your favourite batsman will score this year based on his scoring statistics for past years. We all probably have our own ways of arriving at an estimate! In this article, let us explore one approach.

## ADVENTURES IN PROBLEM SOLVING A Math Olympiad Problem …and a few cousins

In this edition of Adventures in Problem Solving, we study in detail a problem which first appeared in the 1987 USA Mathematics Olympiad. However, we adopt a different strategy this time. Faced with the given problem which looks quite challenging, we tweak it in different ways and obtain related problems which are simpler than the original one. Solving this collection of problems turns out to be a fun activity and demonstrates yet one more time the importance and utility of quadratic functions and quadratic equations.

## Theorem concerning a right triangle

The following elegant geometric result concerning a triangle is based on a problem that appeared in the Regional Mathematics Olympiad (RMO) of 2016.

## Problems for the SENIOR SCHOOL

Here are aset of problems for the senior graders.

## Problems for the Middle School

Invite your middle school students to this set of problems.

## On Problem Posing

Problem-posing and problem-solving are central to mathematics. As a student one solves a plethora of problems of varying levels of difficulty to learn the applications of theories taught in the mathematics curriculum. But rarely is one shown how problems are made. The importance of problem-posing is not emphasized as a part of learning mathematics. In this article, we show how new problems may be created from simple mathematical statements at the secondary school level.

## From a GOLDEN RECTANGLE to GOLDEN QUADRILATERALS and Beyond

This article continues the investigation started by the author in the March 2017 issue of At Right Angles, available at: http://teachersofindia.org/en/ ebook/golden-rectangle-golden-quadrilaterals-and-beyond-1 The focus of the paper is on constructively defining various golden quadrilaterals analogously to the famous golden rectangle so that they exhibit some aspects of the golden ratio phi.

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