







A mathematical expression with the answer 7 
20121110 

emily pose la question : hey um i need to find and problem that fallows bedmas that has one division one multiplication and one sub and one add and one brackets and one exponents that has the answer of number 7 Penny Nom lui répond. 





Sales as a function of advertising 
20101208 

Adori pose la question : The sales S(in thousands if units) of a product after x hundred dollars is spent on advertising is given by S=10(1e^kx). Find S as a function of x if 2500 units are sold when $500 is spent on advertising. Penny Nom lui répond. 





I need to learn to think mathematically 
20100720 

Student pose la question : I need to learn to think mathematically, and like math while doing it, got any ideas, help. Walter Whiteley lui répond. 





Fibonacci and induction 
20100712 

James pose la question : I'm trying to prove by induction that F(n) <= 2^(n1)
where f(1)=f(2)=1 and f(k)=f(k1)+f(k2) for k >=3 is the Fibonacci sequence Stephen La Rocque and Tyler Wood lui répond. 





A proof by induction 
20100325 

SAMUEL pose la question : use mathematical induction to proof that each statement is true for every positve integer n
1/1.2+1/2.3+1/3.4+......1/n(n+1)=n/n+1 Robert Dawson lui répond. 





The nth derivative of x^(n1) log x 
20100310 

shambodeb pose la question : This is a successive differentiation problem by Leibnitz theorem
If y = x^{n1} log x ; Proof nth derivative y^{(n)} = (n1)!/x Harley Weston lui répond. 





A proof by induction 
20100112 

Bhavya pose la question : Prove by induction that if Xi >= 0 for all i, then
(Summation Xi from 1 to n)^2 >= Summation Xi^2 from 1 to n Penny Nom lui répond. 





Show your work 
20090902 

Gerald pose la question : We have a 6th grade student who can solve math problem successfully without showing her work. The teacher thinks it is not fair that she doesn't show her work and the other have to and do. What sort of classroom accommodation(s) would you recommend for this type of student. It would seem to be a popular problem since there are many student who think more global than sequential. Victoria West, Penny Nom and Robert Dawson lui répond. 





Math in everyday life 
20090803 

Naveen pose la question : Dear sir,
We are advised to do a project on "Mathematical modeling to solve various problems
of our everyday life/environmental related problems...... Can u plz help us by mailng some
ideas, suggestion,reference to make my project successful.... Thanking you......
Waiting for your favourable reply...... Penny Nom lui répond. 





Mathematical induction 
20080905 

James pose la question : 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). Victoria West lui répond. 





Mathematical induction 
20080711 

lyn pose la question : can you give me a basic example of a mathematical induction Harley Weston lui répond. 





The sum of the digits of a number 
20080623 

Ben pose la question : Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3. Penny Nom lui répond. 





1/(1x2)+1/(2x3)+1/(3x4)...+1/(n(n+1)) 
20080220 

hossun pose la question : Find a formula for 1/(1x2)+1/(2x3)+1/(3x4)...+1/(n(n+1))
by examining the values of this expression for small values of n.
Use mathematical induction to prove your result. Stephen La Rocque lui répond. 





The Principle of Mathematical Induction 
20071215 

iris pose la question : we have some confusion in our problem. Please help us.
We would like to know "the principle of mathematical induction"
(i) for n=1, p(1) is true.
(ii) assume that for n=k>=1, p(k) is true we have to prove p(k+1) is true. Here (Is n=k>=1 true? or Is n=k.1 true?)
Thanks. Penny Nom and Victoria West lui répond. 





The proof of inequality by mathematical induction 
20061207 

Carol pose la question : S(n) = 2^n > 10n+7 and n>=10 Stephen La Rocque lui répond. 





The Fibonacci sequence 
20061121 

Ross pose la question : Let f0 = 0; f1 = 1,... be the Fibonacci sequence where for all n greater than or equal to 2 fn = fn1 + fn2. Let Q = (1+square root of 5)/2. Show that for all positive n greater than or equal to 0, fn less than or equal to Q^(n1). Penny Nom lui répond. 





Composition of functions 
20061119 

RJ pose la question : Let f0(x) = 2/2x and fn+1 = f0 o fn for n greater than or equal to 0. Find a formula for fn and prove it by mathematical induction. Recall that o represents function composition. i.e., (f o g)(x) = f(g(x)). Stephen La Rocque lui répond. 





Induction 
20061116 

John pose la question : Find a formula for 1/(1x3)+1/(2x4)+1/(3x5)...+1/(n(n+2)) by examining the values of this expression for small values of n. Use mathematical induction to prove your result. Penny Nom lui répond. 





A proof by induction 
20061106 

Zamira pose la question : i have a problem with this mathematical induction: (1^5)+(2^5)+(3^5)+...+(n^5) = ((n^2)*((n+1)^2)*((2n^2)+2n1))/12 Penny Nom lui répond. 





Modelling monthly temperature with a cosine 
20041225 

Regis pose la question : The average monthly temperature for a location in Ontario as a function of month number can be modelled using the equation y = a cos[k(t + b)] + d. Harley Weston lui répond. 





Proof by induction 
20041120 

Vic pose la question : 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) = 2n1 x 3 (equation 1)
Equation 1 must be proven using mathematical induction. This is where I am having a problem. Penny Nom lui répond. 





Proof by induction 
20020220 

Tamaswati pose la question : 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?) Penny Nom lui répond. 





Logico mathematical knowledge 
20020123 

A teacher pose la question : How does young children's logico mathematical knowledge develop? Walter Whitely lui répond. 





Proof by induction 
20011016 

John pose la question : Can you help me with any of these?  For any natural number n > 1, prove that
(4^{n}) / (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
x^{n} + x^{n  2} + x^{n  4} + ... + x^{n} >= n + 1. Penny Nom lui répond. 





Mathematical & conventional meaning of a word 
20011012 

A student pose la question : What is the mathematical & conventional meaning of a word? Like the word Rational or Median. Penny Nom lui répond. 





Proof by induction 
20010930 

Kyle pose la question : I'm trying to learn induction and I need to see how this done please help with this problem... 2^{0} + 2^{1} + 2^{2} +... + 2^{n} = 2^{n+1} 1 is true whenever n is a positive integer. Penny Nom lui répond. 





A sequence of even terms 
20010429 

A student pose la question : A sequence c is defined recursively as follows: c0 = 2 c1 = 4 c2 = 6 ck= 5ck3 for all integers Prove that cn is even for all integers. Leeanne Boehm and Penny Nom lui répond. 





Induction 
20000907 

Joe Peterson pose la question : How do I prove by the principal of mathematical induction? 1.n+2.(n1)+3.(n2)+.....+(n2).3+(n1).2+n.1=(n(n+1)(n+2))/6 Paul Betts lui répond. 





1+4+9+16+...n^2 = n(n+1)(2n+1)/6 
20000601 

Shamus O'Toole pose la question : How do you derive that for the series 1+4+9+16+25.. that S(n)=(n(n+1)(2n+1))/6 Penny Nom lui répond. 





Induction 
20000316 

William Tsang pose la question : I am trying to prove a induction question Sigam r=1 n (2r 1)cube = n square (2 n square  1) Harley Weston lui répond. 





Mathematical deduction and mathematical induction 
20000307 

Espera Pax pose la question : What are mathematical deduction and mathematical induction, and what is the difference between them? Harley Weston lui répond. 





Logic and mathematical logic 
19991006 

Polly Mackenzie pose la question : What is the difference between logic and math logic? Walter Whiteley lui répond. 





Mathematical Induction and the Derivative 
19970318 

Shuling Chong pose la question : "Obtain a formula for the nth derivative of the product of two functions, and prove the formula by induction on n." Any educated tries are appreciated. Penny Nom lui répond. 

