It is always terrifying to learn by heart encrypted information from a painting. Worse, learning by heart is like forgetting very quickly. Hours of memorization that go up in smoke…
“Don’t learn but understand!”
One of my leitmotifs that I hammer my students quite often is “I don’t ask you to learn but to understand!”. Even if understanding strongly promotes memorization, unfortunately, any subject in high school has its share of information to know and to give back. In mathematics, understanding the use of the trigonometric circle is one thing, but it will also be necessary to know how to restore the exact value of the sinus and cosinus from certain angles… In these cases, let your imagination develop, and your mind!
Here are two proposals that I have presented to my students that have greatly simplified the study of the current chapter.
It is enough, then, to visualize the angle of which you are looking for the sinus or the cosinus on a trigonometric circle to determine its sign. Below is a summary sheet.
Below are some exercises for yourself. If you want to get help and review the step-by-step method, click on
Refresh the page to start over with different values.
Consolidate your achievements by attempting this online training series. Don’t hesitate to leave your comments and questions.