I'm happy about this past week. It was quite easy because I already understand logs.
Expanding logs:
1) logAB=logA+logB
2)logA/B=logA-logB
3)logA^B=BlogA
Combining logs is pretty much the opposite.
Also, if a base for the log is not indicated, it is understood to be 10
You cannot combine two logs if the base is not the same.
Changing Base:
1) write in exponential form
2) take the log of both sides
3) solve
Although I understand logs, I do not understand the formulas using Ao and Po. I know you use them when trying to solve word problems, but I don't understand when I am supposed to use which formula. I know that Po is used when the problem states that something is being compounded continually, but as for the two problems that both concern Ao, I do not know. I also do not know how to discern what t, r, and k are supposed to be. If anyone understands this completely and wouldn't have a problem explaining it to me, I would be very grateful.
Subscribe to:
Post Comments (Atom)
there in lies your problem
ReplyDeleteonce you identify what each variable stands for you can decipher which equation to use.
so your three equations are
A(t)=Ao(l+r)^t
A(t)=Aob^t/k
P(t)=Poe^rt
Here are the notes for each variable
Ao=what you start with
Po=what you start with
b=double, half, etc (use this if u see double, half, etc in the problem)
k=time reg. to double, half, etc
t=time
r=rate
So once you know what each variable means deciphering which formula to use when you have a word problem is simple
just write down the informtion given directly by the problem and she which formula the info can be plugged into.
what i mean is if you have a problem that tells you the rate it takes to double you know you'll use the formula with the variable k in it