ECZ 2023 · GCE Paper 2 · Question 2 — Sequences and Series
In a geometric progression, the second term is 21 and the fourth term is 189. Matrix P = 7x-2-x1.
(a(i)) Calculate the first term and the common ratio.[3]
Verified working — step 1
Let first term = a, common ratio = r.(a(ii)) Calculate the sixth term.[2]
Verified working — step 1
T6 = ar5 = 7 x 35 = 7 x 243 = …(a(iii)) Calculate the sum of the first 5 terms of the progression.[2]
Verified working — step 1
Sn = a(r^n …(b(i)) Find the value of x for which the determinant of P is -10.[2]
Verified working — step 1
P = 7x-2-x1(b(ii)) Hence, find the inverse of P.[2]
Verified working — step 1
With x = -2: P = -14-221The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.
Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.
Have a different question?
Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.
Search any past-paper question