What is an exponent?
An exponent is the lazy way of saying, "multiply something against itself a bunch of times."
a*a*a*a*a = a^5 (there were 5 a's so the exponent is 5)
See isn't that shorter?
But along with writing something shorter, you have to learn to use the notation.
Let's learn how you deal with
a^3 * a^4
In long hand that is:
a*a*a * a*a*a*a = a^7
So in other words
a^3 * a^4 = a^(3+4)
Generically that is:
a^x * a^y = a^(x + y)
Multiplying a terms with similar variables, means you need to ADD exponents.
Now let's look at negative exponents.
1/a * 1/a * 1/a = = 1/(a*a*a) = 1/(a^3)
If we look at this example
(a^5)/(a^3) it looks like this in long form:
(a*a*a*a*a)/(a*a*a) = a*a = a^2
So in other words:
a^5/a^3 = a^(5 - 3) = a^2
Dividing terms with similar exponents, is the same as SUBTRACTING the exponents.
Generally speaking:
a^x/a^y = a^(x-y)
Now for the fun part!
If x is smaller than y, the exponent would be NEGATIVE!
a^3/a^5 = a^-2 = 1/a^2
So what does it mean if the exponent is zero????
Let's look at this example.
a^x/a^x = 1
a^(x - x) = 1
a^0 = 1
And that is true for ANY a!
Friday, March 13, 2009
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