The second and fifth terms of a geometric series are 750 and -6 respectively. Find: (1) the common ratio; (2) the first term of the series; (3) the sum to infinity of the series

xn = ar(n-1)(1) x2 = 750 = ar1(2) x5 = -6 = ar4divide second equation by first-6/750 = r3r3 = -0.008r= -0.2Insert into first equation.750 = a * -0.2a = -3750Sum to infinite series = a(1/(1-r))(insert known variables)Sum to infinite series = -3750 * 1/1.2= -3125

HP
Answered by Henry P. Maths tutor

5513 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Express (9x^2 + 43x + 8)/(3+x)(1-x)(2x+1) in partial fractions.


a) Simplify 2ln(2x+1) - 10 = 0 b) Simplify 3^(x)*e^(4x) = e^(7)


Given that y = 3x(^2) + 6x(^1/3) + (2x(^3) - 7)/(3(sqrt(x))) when x > 0 find dy/dx


How do I deal with parametric equations? x = 4 cos ( t + pi/6), y = 2 sin t, Show that x + y = 2sqrt(3) cos t.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences