A sequence is defined as: U(n+1) = 1/U(n) where U(1)=2/3. Find the sum from r=(1-100) for U(r)

Un+1=1/Un where U1= 2/3First of all, we need to find U2 and U3 and so on, up until we notice a pattern in the answers. U2 = 1/(2/3) = 3/2U3 = 1/(3/2) = 2/3As we can see, U1 and U3 are equal, and so we know that for every 'n' that is odd, Un will equal 2/3. This is similar for ever 'n' that even where Un will equal 3/2.Therefore in total for this summation, there will be 50 lots of '2/3' and 50 lots of '3/2' so the answer will be 50(2/3) + 50(3/2) = 325/3

Answered by Maths tutor

4909 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Using the "complete the square" method, solve the following x^2 +4x - 21 =0


What is the tangent line to the curve y = x^3+4x+5 at the point where x = 2?


The General Form of the equation of a circle is x^2 + y^2 + 2gx +2fy + c = 0. Find the centre of the circle and the radius of the circle in terms of g f and c.


Find the turning points of the equation y=4x^3-9x^2+6x?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning