Devin's Make up

How to change bases:
1)rewrite problem in exponential form
2)take the log of both sides
3)move the variable to the front
4)solve
Eg. log5of10=x
5^x=10
log5x=log10
xlog5=1
x=1/log5

Graphing exponential functions (ab^x):
if b is greater than 1, the graph goes up whereas if it is less than one, the graph goes down
Eg. f(x)=5(3)^x the graph would go up because b is greater than one

The formulas are pretty ease but remembering them will be pretty hard and using them in the correct problem will also be kinda hard.

A(t)=Ao(1+r)^t
Ao = what you start with
r = rate
t = time

A(t)=Aob^t/k
Ao = what you start with
t = time
b = double, half, etc.
k = regular time to double, half, etc.
Eg. half-life of 5 days
b = ½
k = 5
A(t)=Ao(1/2)^t/5

P(t)=Poe^rt
Po = wha tyou start with
r = rate
t = time
you only use the problem with p when it says compounding continuously in the problem

then theres the limit thing and rule of 72 (72 / r% = how long it takes to double