Find the sum of the first 3 lowest positive values of x in degrees.
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the main problem with this problem is that it looks tremendously horrible at first sight. i cannot find any good method to solve this. if you have, please do comment
First we write 3 x = Z .. (for simplicity, obviously)
then we write s e c 2 Z = 1 + t a n 2 Z , bring all the terms to the L.H.S, group them, to get our equation:
3 t a n 3 Z + ( 2 − 3 ) t a n 2 Z − ( 2 + 3 ) t a n Z + 3 = 0
From here, it is very easy to observe that t a n Z = 1 satisfies the equation.
Thus, by good-ol' factorisation again and again, we get :
( t a n Z − 1 ) ( t a n Z + 3 ) ( t a n Z − 3 1 ) = 0
From there, calculation yields the 3 lowest positive values of x as:
x = 1 0 ∘ , 1 5 ∘ , 4 0 ∘
Our sum = 6 5