Find the value of x such that 2 x = n = 1 ∏ 2 9 ( 3 + tan ( n ∘ ) ) .
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why you would use the square root of 3 as the inverse of the tan(30º) if you can use directly as the tan(60º) ?
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Because, in my resolution, I've used cotg(30) to represent sqrt3. But I don't know the code to write "cotg" here (do you know?), so I used the inverse of tan(30). Anyway, I didn't realize that using tg(60) works too, thank you!
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In LaTeX editor is \cot {x} that should appear as cot x and you're welcome.
The above expression can be : 2sin(60+x)/cos(x) put consecutively the values and you get x=29.
let α=(3√+tan(1)).(3√+tan(2)).(3√+tan(3))......(3√+tan(29)) Which can be written as α=(3√+tan(1)).(3√+tan(29)).(3√+tan(2)).(3√+tan(28)).......(3√+tan(14)).(3√+tan(16)).(3√+tan(15))
Now,, notice that (3√+tan(1)).(3√+tan(29))=3+3√(tan(1)+tan(29))+tan(1).tan(29)...........(1)
Now we know from the formula that tan(30)=tan(1)+tan(29)1−tan(1)tan(29) Therefore, tan(1)+tan(29)=13√(1−tan(1)tan(29)) , so putting this value in (1), we get (3√+tan(1)).(3√+tan(29))=3+(1−tan(1).tan(29))+tan(1).tan(29)=4
So, like this, all the pairs cancel out to give 4 in each bracket, So, the original problem becomes α=414((3√+tan(15))
Now, we see that (3√+tan(15))=3√+sin(30)1+cos(30)=2
So, the original number α is nothing but, α=(414).2
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Let f ( n ) = 3 + tan ( n ∘ ) .
We know that f ( n ) can be written by:
f ( n ) = tan ( 3 0 ∘ ) 1 + tan ( n ∘ ) = sin ( 3 0 ∘ ) cos ( 3 0 ∘ ) + cos ( n ∘ ) sin ( n ∘ ) = cos ( n ∘ ) sin ( 3 0 ∘ ) cos ( n ∘ ) cos ( 3 0 ∘ ) + sin ( n ∘ ) sin ( 3 0 ∘ ) = cos ( n ∘ ) cos ( 3 0 ∘ − n ∘ ) sin ( 3 0 ∘ ) 1 .
Therefore, n = 1 ∏ 2 9 f ( n ) = sin 2 9 ( 3 0 ∘ ) 1 cos ( 1 ∘ ) cos ( 2 ∘ ) cos ( 3 ∘ ) . . . cos ( 2 9 ∘ ) cos ( 2 9 ∘ ) cos ( 2 8 ∘ ) cos ( 2 7 ∘ ) . . . cos ( 1 ∘ ) = 2 2 9 .
Thus, x = 2 9