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Advanced Math/proving identity of trigo

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Expert: Sherman D. - 7/31/2008


Question
cot x - tan x = 2 cot 2x

Answer
cot(x) - tan(x) = 2cot(2x)

(1/tan(x)) - tan(x) = 2(1/tan(2x))

(1/tan(x)) - (tan(x)^2/tan(x)) = 2/tan(2x)

(1 - tan(x)^2)/tan(x) = 2/tan(2x)


tan(2x) = (2tan(x))/(1 - tan(x)^2)

2/tan(2x) = 2/(2tan(x)/(1 - tan(x)^2))

2/tan(2x) = (2(1 - tan(x)^2))/(2tan(x))

2/tan(2x) = (1 - tan(x)^2)/tan(x)

so

cot(x) - tan(x) = 2cot(2x)

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Sherman D.

Expertise

I can answer questions dealing in mathematics of all kinds except for Physics and Calculus, but i can answer questions in Pre-Calculus and Chemistry. I can also answer questions in Recipes of all kinds. I can find games cheats/walkthroughs, but i can`t find a specific game online or offline. I can also do history and recipes for alcoholic beverages.

Experience

Mathematics, Recipes, History, and Games.

Education/Credentials
High School graduated. I graduated with honors, and i was in Beta Club for a year and a half.

Awards and Honors
Principle's list and A and B honor roll in high school only.

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