# Prove by Principle of Mathematical Induction

• Jul 30th 2011, 06:51 PM
rcs
Prove by Principle of Mathematical Induction
can anybody help me on this pleaseAttachment 21938

thanks so much
• Jul 30th 2011, 07:09 PM
TheChaz
Re: Prove by Principle of Mathematical Induction
1. There is no equation! You might want to chande the "-" into "="
2. Is this true for n = 1? Prove it.
3. If this is true for some k, is this true for k + 1? Write what it would mean for it to be true for k + 1, and then reduce it to the assumed truth of the statement for n = k.
• Jul 31st 2011, 11:26 AM
Re: Prove by Principle of Mathematical Induction
Quote:

Originally Posted by rcs
can anybody help me on this pleaseAttachment 21938

thanks so much

You want to prove the following using the Principle of Mathematical Induction

$1^2+3^2+5^2+.....+(2n-1)^2-\frac{4n^3-n}{3}=0$

Students often wonder what needs to be done on the induction step.

Suppose we had the following scenario....

The equation will be true for n=2 if it is true for n=1.
The equation will be true for n=3 if it is true for n=2.
The equation will be true for n=4 if it is true for n=3.
The equation....... on to infinity.

If the above was true for all pairs of consecutive values of n,
the equation would be true for all n>0, for n natural,
since being true for n=1 would then cause the equation to be true for all n.

We therefore try to show that if the equation is true for any n,
it will therefore be true for the next immediate n.

These 2 consecutive values of n are referred to generally as
n=k
n=k+1

Proving that the equation will be true for n=k+1 if the equation is true for n=k,
proves in general that if the equation is true for any n,
it will also be true for the next n.

Hence, write out the equation for n=k.
Write it out again with k replaced by k+1.

Try to show that if the equation is true for n=k,
then it will also be true for n=k+1.

Show that the equation is true for n=1.
• Aug 10th 2011, 11:52 PM
rcs
Re: Prove by Principle of Mathematical Induction
i would like to say sorry and ask for forgiveness that the one i posted has an error that is instead an equation ... it should be equated by 4k^3-k / 3. this is the correct expression on the Right part of the equation to be solved by PMI... i just need your help on this guys..

Thanks a lot