In the arthmetic sequence, the first term is 3 and the fourth term is 12. Find the common difference (d) and the sum of the first 10 terms.
a. Finding dun = u1 + (n-1)du4 = u1 + (4-1)d12 = 3 + 3dd = 3
b. Sum of first 10 termssn = n/2(2u1 + (n-1)d)s10 = 5(6 + 9d)s10 = 30 + 45(3)s10 = 165
RA
Related Maths IB answers
All answers ▸Three girls and four boys are seated randomly on a straight bench. What is the probability that the boys sit together and the girls sit together.
Determine the coefficient of y^3 in the binomial expansion (2x-3y)^4
Find the coordinates that correspond to the maximum point of the following equation: y = −16x^2 + 160x - 256
Let Sn be the sum of the first n terms of the arithmetic series 2+4+6+... . Find (i) S4 ; (ii) S100 .