shadi shadi
  • 04-04-2015
  • Mathematics
Answered

find the following sum and prove your claim:
(1*2)+(2*3)+..+n(n+1).

Answer :

AliBaghaei AliBaghaei
  • 04-04-2015
1*2+2*3+3*4+...+n(n+1)=
(1²+1)+(2²+2)+(3²+3)+...+(n²+n)=
(1² + 2² + 3² + ... + n²) + (1+2+3+...+n)=
[tex] \frac{n(n+1)(2n+1)}{6} * \frac{n(n+1)}{2} [/tex] =
[tex] \frac{n(n+1)(n+2)}{3} [/tex]
Answer Link

Other Questions

Which ion has the smallest radius 1 O2 2 S2 3 Se2 4 Te2
how many paintings did giuseppe Arcimboldo paint
If the numerator of a fraction is a prime number can the fraction be simplified why or why not
What role did the conversion of Vikings to Christianity play in integrating them into Europe
A square cake is cut into 16 equal parts Ben eats 716 of the cake Belle eats 14 of the cake What fraction of the cake is left Could someone please break it down
How did the initially small slide in stock prices lead to the stock market crash
farid takes 78 teaspoon of allergy medicine every day How much medicine will he take in one week
What is the answer to f299 19 Af8 89 Bf7 89 Cf8 79 there is only three answers to choose from
Which areas did the Mongols conquer and incorporate into their empire 1 China Russia and Iran 2 Axum Zimbabwe and West Africa 3 Spain France and Egypt 4 Japan
Is oxygen a product of cellular respiration