Question

using formula for the sum of first n term of an A.P let 1+2+3+...1000​

Answer 1

Answer:

a=1

d=2-1=1

n=1000

using formula

n/2(2a+(n-1)d)

1000/2(2x1+999x1)

500(1002)

500x1002

Step-by-step explanation:

501000

Answer 2

Step-by-step explanation:

first find Value of n from an formula then insert them Required values in

$sn = n \div 2 (a + l)$