STEP II 2007 question 1 solution - The Student Room
The Student Room

STEP II 2007 question 1 solution

TSR Wiki > Study Help > Subjects and Revision > Mathematics > STEP > STEP II 2007 question 1 solution



i)  \left( 1 + \frac{k}{100} \right)^{\frac{1}{2}} \approx 1 + \frac{k}{200} - \frac{k^2}{80000} + \frac{k^3}{16000000}

a)  \left( 1 + \frac{8}{100} \right)^{\frac{1}{2}} = \left( \frac{27}{25} \right)^{\frac{1}{2}} = \frac{3}{5} \sqrt{3}

So  \sqrt{3} \approx \frac{5}{3} \left( 1 + \frac{8}{200} - \frac{8^2}{80000} + \frac{8^3}{16000000} \right)

 = \frac{5}{3} \left( 1 + 0.04 - 0.0008 + 0.000032 \right) = \frac{5}{3} \left( 1.039232 \right)

 = \frac{10.39232}{6} \approx 1.73205

By long division.

b) Take k=-4. Then:

 \left( 1 + \frac{-4}{100} \right)^{\frac{1}{2}} = \left( \frac{24}{25} \right)^{\frac{1}{2}} = \frac{2}{5} \sqrt{6}

 \sqrt{6} \approx \frac{5}{2} \left( 1 - \frac{4}{200} - \frac{4^2}{80000} - \frac{4^3}{16000000} \right)

 = \frac{5}{2} \left( 1 - 0.02 - 0.0002 - 0.000004 \right) = \frac{5}{2} \left( 0.979796 \right)

 = \frac{9.79796}{4} \approx 2.44949

By long division.

ii)  \left( 1 + \frac{k}{1000} \right)^{\frac{1}{3}} \approx \frac{3000 + k}{3000}

Pick k=29. Then  \left( 1 + \frac{29}{1000} \right)^{\frac{1}{3}} = \left( \frac{1029}{1000} \right)^{\frac{1}{3}} = \left( \frac{3 \times 343}{1000} \right)^{\frac{1}{3}} = \frac{7}{10} \sqrt[3]{3}

So  \sqrt[3]{3} \approx \frac{3000 + 29}{3000 \times \left( \frac{7}{10} \right)} = \frac{3029}{2100}

Solution by SsEe.

Discussions Toggle
Help me shed a few pounds
started by: Megaross
forum: Fitness
replies: 3
last post: 2 Minutes Ago
Blackpool on Tuesdays
started by: Andy6691
forum: General University Discussion
replies: 0
last post: 2 Minutes Ago
Tech Society 3.0
started by: secretmessages
forum: Technology and Computers
replies: 858
last post: 2 Minutes Ago
Housemate is denying he told me he cheated
started by: Anonymous
forum: Friends, Family and Work
replies: 11
last post: 2 Minutes Ago
Getting up for 9am lectures
started by: Station
forum: Student Life
replies: 203
last post: 3 Minutes Ago
Does anyone still believe in the miracle of "green" energy?
started by: chefdave
forum: UK Politics
replies: 12
last post: 3 Minutes Ago
Jews want Arabs to pay 300 Billion for oppression in 1948
started by: Nayred
forum: International
replies: 120
last post: 3 Minutes Ago
Blackpool nighout suggestions (Tuesdays)
started by: Andy6691
forum: University of Central Lancashire (UCLan)
replies: 0
last post: 3 Minutes Ago
Who are your idols from history?
started by: Gurmeet.Kapoor
forum: History
replies: 52
last post: 4 Minutes Ago
Barts and The London Applicants 2012
started by: joemullally
forum: Medical Schools
replies: 3658
last post: 4 Minutes Ago
Most annoying thing people do at University?
started by: The Phelps
forum: Student Life
replies: 241
last post: 4 Minutes Ago
The Porn Industry - celebrating or diminishing feminism?
started by: Marinated_in_Joy
forum: Society
replies: 79
last post: 5 Minutes Ago
The Liverpool FC Thread VII
started by: Mess.
forum: Football
replies: 1950
last post: 6 Minutes Ago
Anyone else seeing University meme pages on their facebook?
started by: -Invidious-
forum: Student Life
replies: 81
last post: 7 Minutes Ago
with the new fees, is going to university even worth it?
started by: ellasmith
forum: Student Financial Support
replies: 17
last post: 8 Minutes Ago
BMO1 - 1997 q5
started by: pi+e=pie
forum: Maths
replies: 20
last post: 8 Minutes Ago
Travelling in London
started by: mespannerhanz
forum: Travel
replies: 17
last post: 8 Minutes Ago
The Somali Society
started by: Sephirona
forum: International Lounge
replies: 3081
last post: 9 Minutes Ago
League of Legends thread
started by: headbuster
forum: Gaming
replies: 398
last post: 9 Minutes Ago
6th Years & Leavers :: Chat Thread #5
started by: Ronar
forum: Scottish Qualifications
replies: 9919
last post: 9 Minutes Ago
Article Updates Toggle
Contact Us | Site Rules | Staying Safe on TSR | Advertising | Staff Blog | Essays & Coursework | Terms & Conditions | Top
Customise your TSR | Life Advice | Hobbies and Interests | Debate and Current Affairs | Study Help | University and University courses
Universities and HE Colleges | Careers, Employment and Gap Years | General Discussion

Customise your TSR