(1)
there is no equation!
what is the right hand side?
(2)
Solve what?
I do not see an equation. There is only a function!
(3)
Taking 'ln' of both sides will not solve it.
Post your work.
Hi. I'm having problems with a few HW problems.
1) log5 (x) + log5 (x+4) = ?
How would I solve this? I get as far as log5 x^2+4x, but then I'm lost.
2) (4x^3 - 5x^2 + 8x -7)/ ( x-1) for x<1
-3x^2 +3x + a for x>=1
solve for a.
I can't seem to get rid of the (x-1) successfully
3) e^(x+3) = e^(x) +7
solve for x
This one seems like it should be simple , but I can't solve it past
x^2 +3x = ln7
I don't really need the answers to these. I would just like to know how to solve them. I've been stuck on them for hours.
Thanks
Wow.. I completely screwed that up.... Sorry about that.
Let's try that again:
1) log5 (x) + log5 (x+4) = k
solve for x in terms of k.
2) (4x^3 - 5x^2 + 8x -7)/ ( x-1) for x<1
-3x^2 +3x + a for x>=1
What value for a will make this function continuous at 1?
3) e^(x+3) = e^(x) +7
For this I first brought the e's to one side so I got:
e^(x+3) - e^(x) = 7
Then I combined them using log(x) - log(y) = log(x/y). I think that's allowed in this case, is it not? After that I got:
e^((x+3)/x) = 7
Then I just used ln to get:
(x+3)/x = ln7
I must have done something wrong, I just don't know what.
(1)
You did the hard job :
We want to remove this noisy log. To do that, you need to apply this formula: . Got it?
(2)
Let f(x) be our function. f is continuous at x=1
(3)
Oh my god!
No No No No No.
The property is valid for the logarithmic functions only, not for the exponential functions.
To solve your eqaution, re-write it as : . Can you complete it now?
Okay. So for problem 1, I got that far, but it just looked funny and I couldn't figure out what to do. The 5^k is what really threw me off. I was trying to get a an integer answer I guess, and gave up. After you let me know I was on the right track, I got the right answer.
2) I got that, and I get the 0/0 which of course means I need to do some work to get rid of the 0/0. However, I can't seem to figure out what to do. I can't get rid of the (x-1). I'm gonna keep working on it though.
3) Lol... sorry for startling you. Now that I look at it, it makes a lot more sense to do what you did. However, sometimes it's just hard for me to see stuff, even though I know the rules, I just can't see that that rule should apply in this situation. At an rate, I got the answer for that one as well.
Thanks for the help. Hopefully I get number 2 on my own, if not, I'll be back.
Also, Is there a sticky for how to post like you did? like get the square root sign instead of typing sqrt, or showing an exponent instead of the carrot (^)? I'm sure I'll be back on these forums, and I think it's easier for everyone to view it like that.