the option with the isoceles triangles can NOT be just of that proof, because nowhere is it defined or proven that there is or are isoceles triangles involved. even though the picture looks like it, but that does not mean anything for the formal proof.

actually, this proof is the same (and is also valid) for non-isoceles triangles.

8 0

3 years ago

What is the sum of the first eight terms of the geometric series 2 + 6 + 18 + 54 + … ?

navik [9.2K]

Hello,
$u_{1} =2\\
 u_{2} =2*3\\
 u_{3} =2*3^2\\
...
 u_{8} =2*3^7\\

\sum_{i=0}^7\ 2*3^i\\
=2(1+3+3^2+...+3^7)\\
=2* \dfrac{3^8-1}{3-1}\\
=2* \dfrac{6560}{2} \\
=6560
$

8 0

3 years ago

Identify the domain of the function.

ruslelena [56]

I believe the answer to your problem is B

7 0

4 years ago