tan 36 degrees, how to find the value. (trigonometric function)

36 degrees is not a special angle. tan 36 degrees is not well known.
but we can calculate the value using the relationship with special angles.
180 degrees is 5 times 36 degrees.
so we can use tan 180 degrees to find tan 36 degrees.
this video shows how to calculate the value of tan 36 degrees by using the addition formula and double angle formula for trigonometric function.
quadratic equations and formula are also involved. (made with vrew)
#sincostan #trigonometry #calculation

[@reelkanha]

Thx for explaining

[@math_travel]

thanks for watching and even a comment.

[@stephenlesliebrown5959]

Yes it is well done! It's a long process without a calculator no matter how it's done. As a suggestion, several times what appears to be a fraction bar or division symbol is used as an underline to emphasize the audio which confused me at first. Examples are 1:24 and at the end for the A substitution. Best, I think, to just write tan 180 degrees=0 and A=x^2. I wish the math world would add 36, 54, 72, and 108 to the list of "special angles" since pentagons and pentagrams turn up a lot. Best wishes to all 🙂

[@math_travel]

thank you for the suggestion. a good idea to include 36 degrees in special angles. that idea gave me a inspiration that special angles are deeply related to shapes.🤓