Question

1cube +2cube +3cube +4cube........90cube solved it

Answer 1

Answer:

16769025

Step-by-step explanation:

Given--->

1³ + 2³ + 3³ + 4³ + ..............................+ 90³

To find ---> Sum of given sequence

Solution----> We know that ,

1³ + 2³ + 3³ + ................+ n³ = n² ( n + 1 )² / 4

Now,

1³ + 2³ + 3³ + ...............+ 90³ = 90² ( 90 + 1 )² / 4

= 8100 × 8281 / 4

= 67076100 / 4

1³+2³+3³ + ............+90³ = 16769025

Additional information--->

1) 1 + 2 + 3 + 4 + .................+ n = n ( n + 1 ) / 2

2) 1² + 2² + 3² + ..........+n² = n ( n+1 ) ( 2n + 1 ) / 6

3) Formula of nth term of AP

aₙ = a + ( n - 1 ) d

4) Formula of sum of n terms of AP.

Sₙ = n/2 { 2a + ( n - 1 )d }

5) Formula of nth term of GP

aₙ = a rⁿ⁻¹

6) Forula of sum of n terms of GP.

Sₙ = a ( rⁿ - 1 ) / ( r - 1 )

#Answerwithquality&BAL

Answer 2

$<font color =“orange”>$

${ \huge \bf{ \mid{ \overline{ \underline{Answer}}} \mid}}$

$\huge\underline{\underline{\texttt{\purple{16769025}}}}$

#answerwithquality #bal