How do you find the sum of the series #3i# from i=1 to i=6?

1 Answer
Oct 23, 2016

Answer:

The sum of the series is 63.

Explanation:

Use the summation property #sum_i ^n ca_i = csum_i ^n a_i#, where c is a constant.

#sum_1 ^6 3i=3*sum_1 ^6 i#

Use the summation property #sum_(x=1) ^n x = frac{n(n+1)}[2}#

#3* sum_1 ^6 i= 3 *frac{6(6+1)}{2} = 63#

Alternatively, you could substitute i =1, i=2, i=3,...i=6 into 3i and then add.

#3(1) +3(2)+3(3)+3(4)+3(5)+3(6) = 63#