I understand how to \"plug & chug\" with this formula: T(n)= floor(n*(n+2)*(2n+1
ID: 3107630 • Letter: I
Question
I understand how to "plug & chug" with this formula: T(n)= floor(n*(n+2)*(2n+1)/8) Freidrich's formula, but I don't understand how each part (like why "n+2 and why divide by 8) directly relates to finding the total number of triangles in a triangle, such as a 10x10x10 triangle.
I understand that in this example, that n=10. Therefore, T(10)= floor(10*(10+2)*(2*10+1)/8)= 315.
So, my real ONE question is how does this formula work to actually show the total number of equilateral triangles inside one large equilateral triangle???????
Explanation / Answer
by induction we have to provethis.
since Freidrich already done that.
we can use.
else
take induction process.
prove that it istrue for n =1
then prove that n =k+1
then you are done !!