19 items are filed under this topic.
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Prove by induction |
2009-10-02 |
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From Anonymous: How can you prove the following by induction:
Any fraction (A / B), where 0 < (A / B) < 1, can be expressed as a finite sum
(1 / c(1)) + (1 / c(2)) + (1 / c(3)) + ... + (1 / c(k)),
where c(1), c(2), ..., c(k) are natural numbers greater than 0.
[ex. (20 / 99) = (1 / 9) + (1 / 11)] Answered by Claude Tardif. |
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Mathematical induction |
2008-09-05 |
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From James: I need to prove a problem by induction regarding the Triangle Inequality. The problem is
abs(a1 + a2 +...+an) <= abs(a1) + abs(a2) +...+ abs(an). Answered by Victoria West. |
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cos(n)pi = (-1)^n |
2006-12-14 |
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From Idrees: How can I prove the following: cos(n)pi = (-1)^n Answered by Steve La Rocque. |
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A proof by induction |
2006-10-02 |
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From Zamira: i'm studying induction but i don't get how to proof that 1+2+2^2+2^3+...+2^(n-1) = (2^n) - 1. Answered by Penny Nom. |
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Proof by induction |
2006-04-24 |
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From Meshaal: Find an expression for:
1-3+5 - 7 + 9 - 11 + ... + (-1)^(n-1) * (2n-1)
and prove that it is correct.
Answered by Stephen La Rocque. |
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Proving a summation formula by induction |
2006-04-19 |
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From Sharon: Prove by induction that the sum of all values 2^i from i=1 to n equals 2^(n+1) - 2 for n > 1. Answered by Stephen La Rocque. |
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A proof by induction |
2006-04-09 |
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From Sharon: prove by induction: For every n>1, show that
2 + 7 + 12 + ...+ (5n-3) = n(5n-1)/2 Answered by Penny Nom. |
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Proof by induction? |
2005-08-10 |
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From Peter:
I am a lecturer and am having a problem with the following Proof by
Induction.
If
(N x N x N x N) + (4 x N x N x N) + (3 x N x N) + (N) = -4000
Prove that N is even!
Answered by Chris Fisher and Penny Nom. |
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Proof by induction |
2004-11-20 |
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From Vic: Problem: Find the first 4 terms and the nth term of the infinite sequence defined recursively as follows:
a(1) = 3 and a(k+1) = 2a(k) for k -> 1.
Note: Quantities in brackets are subscripts
-> means 'equal to or greater than'.
Using the recursive formula, the first 4 terms are;
a(1) = 3, a(2) = 6, a(3) = 12, a(4) = 24
The nth term a(n) = 2n-1 x 3 (equation 1)
Equation 1 must be proven using mathematical induction. This is where I am having a problem. Answered by Penny Nom. |
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n! > n^2 |
2004-03-30 |
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From Jose: How can you prove by mathematical induction that:
n! > n2. Answered by Penny Nom. |
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Proof by induction |
2004-03-02 |
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From Chris: I need some help of how to solve the problem
"use the principle of mathematical induction to prove that the following are true for all positive integers"
cos(n x pi + X) = (-1)^n cosX
any help would be appreciated Answered by Penny Nom. |
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Proof by induction |
2002-09-26 |
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From Pooh: Use induction to show that
1 2 + 2 2 + .....+n 2 = (n 3)/3 + (n 2)/2 + n/6 Answered by Paul Betts. |
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Proof by induction |
2002-08-31 |
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From Tabius: Use mathematical induction to prove that the following formulae are true for all positive integers: a) 1 + 3 + 5+...+(2n - 1) = n 2 b) 2 n > n. Answered by Penny Nom. |
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Proof by induction |
2002-02-20 |
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From Tamaswati: How do I prove the assertion that "the determinant of an upper triangular matrix is the product of the diagonal entries" by mathematical induction? (Before I check this assertion for a few values of n how do I rephrase the assertion slightly so that n appears explicitly in the assertion?) Answered by Penny Nom. |
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Proof by induction |
2001-10-16 |
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From John: Can you help me with any of these? - For any natural number n > 1, prove that
(4n) / (n + 1) < [(2n)!] / [(n!)2].
- For any natural number n > 1, prove that
1/sqrt(1) + 1/sqrt(2) + 1/sqrt(3) + ... + 1/sqrt(n) > sqrt(n).
- For any natural number n and any x > 0, prove that
xn + xn - 2 + xn - 4 + ... + x-n >= n + 1. Answered by Penny Nom. |
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Proof by induction |
2001-09-30 |
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From Kyle: I'm trying to learn induction and I need to see how this done please help with this problem... 20 + 21 + 22 +... + 2n = 2n+1 -1 is true whenever n is a positive integer. Answered by Penny Nom. |
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Harmonic numbers |
2001-05-23 |
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From Leslie: The harmonic numbers Hk, k = 1,2,3.....are defined by Hk = 1 + 1/2 + 1/3....1/k I am trying to prove by mathematical induction: H2n >= 1 + n/2 , whenever n is a nonnegative integer. H8 = H23 >= 1 + 3/2 Can you help? Answered by Harley Weston. |
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Induction |
2000-09-07 |
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From Joe Peterson: How do I prove by the principal of mathematical induction? 1.n+2.(n-1)+3.(n-2)+.....+(n-2).3+(n-1).2+n.1=(n(n+1)(n+2))/6 Answered by Paul Betts. |
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Induction |
2000-03-16 |
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From William Tsang: I am trying to prove a induction question Sigam r=1 n (2r -1)cube = n square (2 n square - 1) Answered by Harley Weston. |
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