SRL Archive - News and General

I was helping my girlfriend with her maths tonite (Year 10) and I got stuck on a question!! Which is really annoying for me because I just got 94% on my Stage 1 (Year 11) Maths Exam..
So now im on holidays and im not going to be able to get this equation out of my head until I remember how to isolate this indicie.

I know im just forgetting some stupid rule.. but its really getting to me!
Anyway, heres the equation

200 = 25*(1.26)^n

Thats it, I just cant solve for n :(

√
That will do for square root, just copy that and paste when you need it :P

I think

N = 3

Not 100% sure but i think it is..

I rounded() all the squareroots etc..

Nar it cant be.
if n = 3
:. 25 * (1.26)^3 = 50.0094
and 50.0094 <> 200

But thanks for trying :)

Its not so important finding out what n is, I just need to know the rule for isolating an indicie/exponent.

 200 = 25*(1.26)^n  // original equation
   8 = 1.26^n   //simplify
log8 = log(1.26^n)  // log both sides
log8 = n*log1.26   //move the n down (one of the log rules)
   n = log 8 / log 1.26  //solve for n
     = 8.997559857
       

If you don't know logarithms are the inverse of indices so

 y = a^x <--> x = loga(y) //the 'a' is supposed to be subscript in proper maths setting out

Yay Logarithms!! I remember now!!
I love you man, thanks so much.
I can sleep tonight :)