Getting bored in my history class I started drawing some amazing triangles .
Starting from to then to and then again to (loop). Now extending to such that . Joining and extending to such that . Again joining and and extending to such that and so on indefinitely without lifting the pen (as shown in figure).
Denote the following symbols:
be the set containing lines parallel to .
be the set containing lines parallel to .
be the set containing lines parallel to or .
be the set containing lines parallel to or .
As i was getting extremely bored i drew 59 lines (assume)
We further denote the following:
Now the monic quartic equation whose roots are is "double derivated" (double differentiated) and it can be represented as .
Find the value of .
Details and Assumptions
are also included in the corresponding sets.
Consider and so on single line segments instead of two line segments.
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First, define L n as the n t h line drawn by the speaker, so that L 1 = A B , L 2 = B C , L 3 = C D , L 4 = D E , and so forth. Notice that L 1 ∣ ∣ L 5 , L 2 ∣ ∣ L 6 , L 3 ∣ ∣ L 7 , a n d L 4 ∣ ∣ L 8 . More generally, L n ∣ ∣ L n + 4 , so the set of lines parallel to L n will include all lines L m where m ≡ n ( m o d 4 ) and m ≤ 5 9 since the speaker drew only 59 lines. This now gives
γ = { L 1 , L 5 , L 9 , . . . , L 5 7 } , n ( γ ) = 1 5
β = { L 2 , L 6 , L 1 0 , . . . , L 5 8 } , n ( β ) = 1 5
Δ = { L 3 , L 7 , L 1 1 , . . . , L 5 9 } , n ( Δ ) = 1 5
Θ = { L 4 , L 8 , L 1 2 , . . . , L 5 6 } , n ( Θ ) = 1 4
so the quartic polynomial with the above numbers as its roots will be of the form c ( x − 1 5 ) 3 ( x − 1 4 ) where c is a constant. For the purpose of this solution, let c = 1 so that the needed polynomial is ( x − 1 5 ) 3 ( x − 1 4 ) = x 4 − 5 9 x 3 + 1 3 0 5 x 2 − 1 2 8 2 5 x + 4 7 2 5 0 . Differentiating this polynomial twice gives d x 2 d 2 ( x − 1 5 ) 3 ( x − 1 4 ) = 1 2 x 2 − 3 5 4 x + 2 6 1 0 .
Finally, the answer is obtained by adding 1 2 + 3 5 4 + 2 6 1 0 + 2 4 = 3 0 0 0