Mathematical induction is a mathematical proof technique. It is essentially used to prove that a statement P(n) holds for every natural number n = 0, 1, 2, 3, . . . ; that is, the overall statement is a sequence of infinitely many cases P(0), P(1), P(2), P(3), . . . . Informal metaphors help to explain this technique, such as falling dominoes or climbing a ladder:
Mathematical induction proves that we can climb as high as we like on a ladder, by proving that we can climb onto the bottom rung (the basis) and that from each rung we can climb up to the next one (the step).
A proof by induction consists of two cases. The first, the base case (or basis), proves the statement for n = 0 without assuming any knowledge of other cases. The second case, the induction step, proves that if the statement holds for any given case n = k, then it must also hold for the next case n = k + 1. These two steps establish that the statement holds for every natural number n. The base case does not necessarily begin with n = 0, but often with n = 1, and possibly with any fixed natural number n = N, establishing the truth of the statement for all natural numbers n ≥ N.
The method can be extended to prove statements about more general well-founded structures, such as trees; this generalization, known as structural induction, is used in mathematical logic and computer science. Mathematical induction in this extended sense is closely related to recursion. Mathematical induction is an inference rule used in formal proofs, and in some form is the foundation of all correctness proofs for computer programs.Although its name may suggest otherwise, mathematical induction should not be confused with inductive reasoning as used in philosophy (see Problem of induction). The mathematical method examines infinitely many cases to prove a general statement, but does so by a finite chain of deductive reasoning involving the variable n, which can take infinitely many values.
Hi,
I was designing a High Power High frequency Induction Heater inverter. I've choose H-bridge configuration for the inverter
and IR2110 gate drivers to drive the bridge. As the IR2110 is a half-bridge driver i'll use two of them to drive the both sides.
I've done a rough circuit(just...
Homework Statement
Show that the principle of mathematical induction and strong induction are equivalent; that is, each can be shown to be valid from the other.
Homework Equations
Weak induction:
(P(1) \wedge \forall k (P(k) \rightarrow P(k+1))) \rightarrow \forall n(P(n))
Strong...
Homework Statement
Show that it is possible to arrange the numbers 1, 2, ... n in a row so that the average of any two of these numbers never appears between them. [Hint: Show that it suffices to prove this fact when n is a power of 2. Then use mathematical induction to prove the result when n...
I understand that electromagnetic induction is determined because of a moving electric charge in a magnetic field, but why is the motion necessary? Why is it that motion causes electromagnetic induction and it isn't possible without motion?
Homework Statement
Suppose a and b are real numbers with 0 < b < a. Show that, if n is a positive integer, then
a^n - b^n \leq na^{n-1}(a-b)
Homework Equations
The Attempt at a Solution
I'm trying to show this by induction.
Let P(n) be the proposition that a^n - b^n \leq na^{n-1}(a-b)...
I'm willing to say that I have a fair understanding of Electromagnetism, at least from a classical perspective, but I was never entirely clear about the difference between, say, the time-varying magnetic field created by an inductor and the Electromagnetic field of light in general. Based on...
Homework Statement
2n-1
Sigma (3i+1) = n(6n-1)
i=0
prove for all positive n
Homework Equations
The Attempt at a Solution
It holds true for n=1
5=5
then P: m+1
2m+1
Sigma(3i+1) = (m+1)(6(m+1)-1) or 6m^2 + 11m + 5
i=0
then 2m+1
Sigma(3i+1) = m(6m-1) +...
Homework Statement
Let Tn(x)=cos(narccosx) where x is real and belongs to [-1,1] and n E Z+
Find T1(x).
Show that T2(x)=2x^2 - 1.
Show that Tn+1 (x) + Tn-1 (x) = 2xTn(x)
Hence, prove by induction that Tn(x) is a polynomial of degree n.
The Attempt at a Solution
Since cosθ=x and arccosx=θ
we...
1. I don't understand how to prove this.
for all n≥1, 10n - 1 is divisible by 9.
3. I've done the basis step.
Now I'm on the inductive step.
I'm using (10k+1-1)/9=1.
I don't know where to go from there.
Using algebra just gets me down to 10k+1= 10. And I really don't think that's...
Prove by induction that n^2 + n ≤ 2^n
for all integers n≥5
How i did:
Case(1)
Suppose that n = 5
LHS = 5^2 +5 = 30
RHS = 2^5 = 32
30 ≤ 32
Ok LHS ≤ RHS
Case (2)
Suppose that's true for n=p≥5. Show that its true for n = p+1
What should i do next ? I had a memory loss here :(
Suppose you are building a sequence consisting of 0 and 1 in such a way that:
- you start with 1
- no consecutive 0s are allowed
Examples of such sequences are: 1, 1010, 110111101 etc. Empty sequence is also allowed.
I want to prove by induction that the number of 0s in such a sequence is...
Homework Statement (
Given: U0=2 and :
(U)n+1=(Un^2+Un)/(1+Un)
Homework Equations
prove that for every n in N : Un>1
The Attempt at a Solution
ok for n=0 i got Un+1=2 and 2>1 therefore for n=0 its true.
now we assume its true for U=0 and we want to show that Un+1>Un...
Homework Statement
The Attempt at a Solution
I'm not really sure where to start with this one. I know that in steady state the capacitor will become an open circuit and the inductor a short circuit.
I first changed the current source to a thevenin equivalent of 1.2mV. I don't...
Homework Statement
Prove by induction that gamma(v+1)(v+1)(v+2)...(v+k)=gamma(v+k+1) for k=1,2,3...
Homework Equations
Really just using the relation x*gamma(x)=gamma(x+1)
The Attempt at a Solution
for a basis gamma(v+1)(v+1)=gamma(v+1+1)
so holds for k = 1
inductive...
Hi there. I have a current I running throught a tesla spiral coil, and I have to compute the magnetic field at the center of it. The tesla coil has N turns, and an inner radius a, and outer radius b.
This is the tesla spiral coil:
The courrent enters through the outer cable, and goes out...
Hello!
Not sure if this should go here, but it's from a physics textbook.
I was reading about charge by induction and the use of an Earth to achieve this.
Here's a wonderfully detailed and exquisite image that took many laborious hours to construct. The red and black Earth's are not intended...
Hello everybody,
I am doing my reading lately to prepare for some exams to join a mathematics department.
And I would very much like, if anyone could help, the solution (or a hint) to the following induction proof.
" Show that n^3 + (n+1)^3 + (n+2)^3 is a multiple of 9 "
:smile:
I...
Homework Statement
http://dc10.arabsh.com/i/03594/qn9gr42q192z.png
What is the direction of current in ring 2 if :
a) ring 2 moves towards ring 1
b) ring 2 moves away ring 1
The Attempt at a Solution
I used Fleming right hand rule but I'm not sure if it is true,
a) the...
I remember my discrete math course in university, where professor told that we can apply induction only to discrete sets. Yet, neither Wikipedia nor Google say nothing about countability importance for induction. They say that underlying set must be well-ordered. The well-ordering topic says...
Hello
Can you please assist to obtain information, as explained and requested below:
We are trying to minimize downtime for failure of induction furnace lining and hence we are exploring all possible ways and means to achieve the same.
The situation in our plant has...
I've been looking into the induction heating a bit lately and have come up with a few questions.
One is in regards to hysteresis losses. I know what hysteresis is and how it contributes to the heat generation, but how much of an effect does it actually have? Some articles I've read have...
Hi everyone, I have been trying to do this induction question... but can't seem to understand how to do it.
Prove by induction that, for all integers n is greater than or equal to 1,
(n+1)(n+2)...(2n-1)2n = 2^n[1x3x...x(2n-1)]
This is what someone else has given as the answer:
For n...
Suppose that the stator of an induction motor is connected to grid and the rotor is run faster than the synchronous speed. Now the current direction in the rotor circuit reverses because air gap flux as seen by the rotor rotates in reverse direction at slip speed. To maintain the same flux in...
Hello folks.
I have an electromagnetics quiz tomorrow and I am kind of nervous. I can't seem to grasp the concept of induction, more importantly how it differs in AC and DC circuits.
So in lay terms: Induction is production of electric current across a conductor which is moving through or...
I was just wondering if anyone knew of software that would allow me to simulate magnetic induction.
I'm researching into the effects distance and the number of windings has on the effect of transfer efficiency between two coils.
I've seen lots of people mention Maxwell, but they seem to...
I will prove the false statement, that n\geq a\Rightarrow n!\geq a^n, n\in \mathbb{N}-\left \{ 0 \right \} with induction
For n=1 1\geq a\Rightarrow 1!\geq a^1\Rightarrow 1 \geq a which is true.
Suppose that n\geq a\Rightarrow n!\geq a^n, n\in \mathbb{N}-\left \{ 0 \right \}
Then...
Hi all,
I'm trying to understand induction heating, specifically if there can be inductive heating without a coil, simply power applied through a hairpin-shaped resistor. Imagine a big hair-pin-shaped resistor with power applied to one leg - near the bottom of these legs are small metal...
Homework Statement
Prove by induction that a polygon with n angles has Mn = (n-3)n/2 diagonals.
Homework Equations
We assume that the formula Mn+1=Mn +n - 1 is correct.
The Attempt at a Solution
First of all I checked if the 1st formula is correct for n=3 (a triangle)...
Homework Statement
A single-turn circular loop of radius R = 0.235 m is coaxial with a long 1780 turn solenoid of radius 0.0435 m and length 0.850 m, as seen in the figure below. The variable resistor is changed so that the solenoid current decreases linearly from 6.12 A to 1.46 A in 0.230...
Homework Statement
Let x ∈ N. Show that there exists for each n ∈ N a natural number denoted by x^n (this is just a notation, but should tell you what we are doing)such that x^1 =x and x^σ(n) =x·x^n.
Homework Equations
σ(n) = n + 1
The Attempt at a Solution
So far my answer is...
Homework Statement
A single-turn circular loop of radius R = 0.235 m is coaxial with a long 1780 turn solenoid of radius 0.0435 m and length 0.850 m, as seen in the figure below. The variable resistor is changed so that the solenoid current decreases linearly from 6.12 A to 1.46 A in 0.230...
Hi, I have to solve this problem... I have done something, but I don't know if it is right :/ Thanks a lot for your help!
"Show by induction that (1-nu)(1+u)<=1 for n=0,1,2,3... and u>-1"
For n=0:
(1-0*u)(1+u)^0 <=1
1*1<=1
1<=1, which is true.
Assume that the statement is true for...
Homework Statement
My induction proof was really easy and simple, and people were having problems and doing substitutions and other complicated things. Normally I'd take pride in making a simpler proof but, there are really brilliant people in this class and I'm just starting to get the...
What will happen if an induction motor is fed from rotor side. I mean if i supply say 50HZ frequency supply to rotor through slip rings and have my stator windings connected to variable resistances will the rotor start to rotate and if it does in which direction?
Hello!
I am making som calculations on induction heating of a metallic cylinder inside
a solenoid through which an AC current passes, but the answer I get seems to
be completely unrealistic (10 kW with a 50 Hz, 5 Amps, 230 V rms), but I can't seem
to find my mistake.
What I think is...
This isn't a homework question as such, but according to my physics book in electricity it is always the negative (electrons) charge that move. Is it possible to charge something negatively via induction?
I mean the last step in the process is earthing the object, if you Earth it, do positive...
Homework Statement
When we place a magnet in a long coil of wire the emf will be maximum when the magnet is at either end. What would happen when the magnet lies in the middle of the coil (i.e: the same amount of flux is interacting with the coil at all times). Would we have an induced EMF...
Homework Statement
I have been studying induction for a few days now and am able to produce some proofs, but have some inquiries as to its theory. First, in strong induction, it seems that different sources disagree on whether base cases are necessary to include within the proofs. Is there...
Homework Statement
For each positive integer n, let S_{n} = \frac{1}{n(n+1)} + \frac{1}{(n+1)(n+2)} + ... + \frac{1}{(2n-1)2n}.
(a) Calculate S_{1}, S_{2}, S_{3}. Then use this data to guess a simple formula for S_{n}.
(b) Prove your guess in part (a) by mathematical induction
(c) Use Result...
Homework Statement
Okay, so I'm going to be completely honest, I am really bad at math, and I have been struggling the past couple of weeks in my Quantitative Reasoning class. I am so lost. I don't know if it's my teacher's teaching method or what, but nothing is clicking for me at the moment...
Homework Statement
Sn=1-3+5-7...+(-1)^n(2n+1)Homework Equations
Show that Sn=(-1)^n(n+1)
The Attempt at a Solution
S(n+1)=Sn+(-1)^(n+1)*(2n+3) = (-1)^n*(n+1)+ (-1)^(n+1)*(2n+3)
S(n+1)= (-1)^(n+1)*[(2n+3)-(n+1)] (because (-1)^(n+1)= - (-1)^n )
S(n+1)=(-1)^(n+1)*(n+2)
is that correct proof
hi
Here is a problem I am trying to do ..
Show that it is possible to arrange the numbers 1, 2, . . . , n
in a row so that the average of any two of these numbers
never appears between them.
Here is my attempt. The base case will consist of first two numbers.
So
Base Case: n=2
The...
Homework Statement
So we have to prove that \frac{(n+1)(n+2)(n+3)...(2n)}{1*3*5...*(2n-1)} = 2n2. The attempt at a solution
I. For n=1, obviously the proposition is true. (2*1/(2-1) = 2^1 = 2)
II. Let n=k and assume \frac{(k+1)(k+2)(k+3)...(2k)}{1*3*5...*(2k-1)} = 2k.
Now, for n=k+1 we...
Homework Statement
Prove that 8 divides: 1+2x3^(n-1)+5^n for every natural number : n>0Please I'm having difficulties solving this problem, i just want to understand the concept of how to solve it thank you.
I know that 8 divides: 1+2x3^(n-1)+5^n can also be written as 1+2x3^(n-1)+5^n=8k ...
A professor the other day used an induction coil power a crt tube like the one at the link below.
http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=99
I understand the general idea of both induction coils and crts, but what confuses me is...
Greetings,
I have read the explanation on this forum here: https://www.physicsforums.com/showthread.php?t=441637 which discusses Faraday's Law of Induction, but I'm having a hard time understanding how to extrapolate that to my problem.
My goal:
Construct a circuit that measures ambient...
Can someone please tell me why the magnetic field makes the electrons flow round the coil in a generator? Does the force of the magnetic field have to go in the same direction as the coil?
Homework Statement
2^{2n-1} + 3^{2n-1} is a number divisible by 5.
Prove by induction.
Homework Equations
The Attempt at a Solution
Firstly, solving for n = 1 is true.
I've re-written the statement to be:
2^{2n-1} + 3^{2n-1} = 5L
where L is any natural number...