Trigonometry - Double Angle Formulae
In this video you are shown how the double angle formulae are derived from the addition formulae
Double Angle Formulae
I want to make maths freely available to all students throughout the world. Over 1500 videos have been completed so far and more go up most days, see my facebook page. If you can offer a donation to keep this project alive and/or like a page, then this is really appreciated. To make a secure donation, please click the button on the right. Thankyou. More ...