Help wirh mathematical induction (1 Viewer)

[SpiralFlex]

Hi, im dont understand this bit
(3^k - 1 + 2 x 3^k)/2 = (3 x 3^k - 1)/2
Can u elaborate??
But thanks for the help

I will write it like this



And then rewrite it like this:



From the numerator, if we have ONE lot of 3^k and we add it to TWO lots of 3^k, isn't that the same as saying THREE lots of 3^k?





Now using your indice laws

 

[littlesmallworld]

Ahhhhh i understand now haha thats smart

 

[hit patel]

My questions remains unanswered yet.

 

[littlesmallworld]

I also need help with this question.
The sum of n terms of an arithmetic sequence whose first term is a and common difference d is
n/2(2a + (n-1)d)

 

[RealiseNothing]

But spiral for the fiirst question according to textbook we are required to prove : 2+4+6+.....+2k+ (2k+1) + 2(k+1) = (k+1)((k+1)+1)

However for the second question you and I am right.

It's wrong.

 

[hit patel]

You sure ? Terry Lee also told me its right?

 

[RealiseNothing]

You sure ? Terry Lee also told me its right?

Fine, it's right if that's the answer you're looking for.

 

[hit patel]

? Damn ? Heroic? Panda, Sy123 where r u? Can u tell me if Terry Lee or RealiseNothing is right?