Proving Induction: n4 <= 4n + 17 | Math Algebra Homework

  • Thread starter lovemake1
  • Start date
In summary, Homework Equations states that for all natural numbers n, n4 <= 4n + 17. The base case is 0, and it is proved that 4n4 <= 4(4n + 17) using 4n+1 + 17 as the required value. It is still unclear how to solve for n given that the equation only allows for addition.
  • #1
lovemake1
149
1

Homework Statement

The induction question is. for all natural n, n4 <= 4n + 17Base case: 0 Works, since 0 < 1 + 17 then,
I assume that for all n in natural, n4 <= 4n + 17 holds.Now I believe I need to show that, 4(n4) <= 4(4n + 17)
that is, 4n+1 + 17 >= (n+1)4
To do so, I prove, 4n4 >= (n+1)4,
which proves that 4n+1 + 17 >= (n+1)4How would I prove.. 4n4 >= (n+1)4 = n4 + 4n3 + 6n2 + 4n + 1

This step is in the middle of my induction proof and it is neccesary part of my induction step.

How would I go about doing this?
Some easier version similar to this deals with power of 2 or n, which seems rather simple. but, this one I am having hard time.
Help is much appreciated.

Homework Equations


The Attempt at a Solution



I tried starting from n4 = n4 and start adding things to both sides but the onlything I can add to left is n4 so I am not entirely sure how to go about doing this type of math. please some tricks and help is appreciated.
 
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  • #2
lovemake1 said:

Homework Statement



I am working on an induction problem but somehow I need to prove.
using algebra and such. 4n4 > (n+1)4 = n4 + 4n3 + 6n2 + 4n + 1

This step is in the middle of my induction proof and it is necessary part of my induction step.

How would I go about doing this?

Homework Equations



The Attempt at a Solution



I tried starting from n4 = n4 and start adding things to both sides but the only thing I can add to left is n4 so I am not entirely sure how to go about doing this type of math. please some tricks and help is appreciated.
Please state the whole problem as it was given to you.

You're more likely to get help that way.

Also, at least sketch out your solution up to the point you're having trouble. It's hard for us to guess what you're trying to accomplish otherwise.
 
  • #3
Agreed, for example this expression certainly isn't true for n=1, so for the induction to take place, where are you starting from?
 
  • #4
oay said:
Agreed, for example this expression certainly isn't true for n=1, so for the induction to take place, where are you starting from?


I added the full question with my understandings.
 
  • #5
oay said:
Agreed, for example this expression certainly isn't true for n=1, so for the induction to take place, where are you starting from?

sorry I fixed the problem. it's >= instead of >
thanks,
 
  • #6
lovemake1 said:
I added the full question with my understandings.

But you've changed the whole question since you last asked it. It is now a mess. Unless you yet again change it.

And n4+1 is not the same as 4n4 which is how you have it written here, before you change it again!
 

1. What is algebra and why is it important?

Algebra is a branch of mathematics that deals with the manipulation of symbols and equations to solve problems. It is important because it helps us understand relationships between quantities and patterns, and can be used to solve real-world problems in fields such as science, engineering, and economics.

2. What is the difference between arithmetic and algebra?

Arithmetic is the basic process of performing operations on numbers, while algebra involves using symbols to represent numbers and solving equations and expressions. In algebra, we can manipulate these symbols to find solutions to equations, while in arithmetic, we simply perform operations on numbers.

3. What is mathematical induction and how is it used in algebra?

Mathematical induction is a method of proving the truth of an infinite number of statements by proving that a specific statement is true, and then showing that if the statement is true for one value, it is also true for the next value. In algebra, mathematical induction is often used to prove theorems or to solve certain types of equations.

4. What are variables and how are they used in algebra?

Variables are symbols that represent unknown quantities in an equation or expression. They are used in algebra to represent any number or value, allowing us to solve for the value of the variable in an equation or to express relationships between variables.

5. How can I improve my algebra skills?

Practice is key to improving your algebra skills. Start by mastering the basic concepts and operations, and then move on to more complex problems. It can also be helpful to seek out resources such as textbooks, online tutorials, and practice problems to reinforce your understanding and skills. Additionally, seeking help from a teacher or tutor can provide valuable guidance and clarification on difficult concepts.

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