# math

posted by on .

Solve the following equation.

log4(x+2)=lo4^7

Both of the 4's should be dropped down.

• math - ,

did you mean

log4 (x+2) = log4(x^7)
or
log4(x+2) = (log4x)^7
or
....

your right side of the equation makes no sense

• math - ,

log lower 4(x+2)=log lower 4 7. does this make sense know? How do you make the lower sign to be able to get the 4 lower??

• math - ,

I wasn't worried about the lower case, I questioned the

log4^7
it makes no sense

that is similar to something like
√^7 or tan ^7

you take the log "of something" you can't just have have log

I had guessed that there would be an x of sorts, since the left side contained the variable x

• math - ,

it is written as you have it written the first time. I couldn't make out the question. It made no sense to me.

• math - ,

ok, if it is
log4 (x+2) = log4(x^7)

then x+2 = x^7 , (I "un-logged it)

x^7 = x+2 is a very nasty equation to solve, which is way beyond the scope of these kind of posts

You could use something like Newtons method

let y = x^7 - x - 2
dy/dx = 7x^6 - 1

new x = x - (x^7 - x - 2)/(7x^6 - 1)

pick any reasonable value for x
say x = 1 , (I know it does not work)
newx = 1 - (1-1-2)/(7-1)
= 1 - (-2/6) = 1.333333
make that your next x, and using a calculator
new x = 1.3333 - (....
= 1.22485...

...

newx = 1.1846
newx = 1.17975..
newx = 1.179693902
newx = 1.179693891
newx = 1.17969389 , wow, isn't that amazing