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Algebra and Functions Videos 30 videos
Algebra and Functions: Drill Set 4, Problem 1. Which of the graphs fits the equation?
Algebra and Functions: Drill 4, problem 2. If the function for the area of a circle with respect to its diameter was graphed in the first quad...
Algebra and Functions: Drill 4, Problem 3. The sum of the quadratic parent function and the line given has which of the following as its graph?
CAHSEE Math 3.2 Algebra and Functions 193 Views
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Description:
Algebra and Functions: Drill Set 3, Problem 2. Simplify the expression in this video.
Transcript
- 00:03
And here's your shmoop du jour.
- 00:05
Simplify the expression 2a to the fourth times 4a to the negative second.
- 00:10
Here are the potential answers...
- 00:12
Before we spoil the ending, hit pause and try it yourself.
- 00:18
Remember order of operations, or PEMDAS?
Full Transcript
- 00:21
Please excuse my dear aunt sally... or parentheses, exponents, multiplication/division, and addition/subtraction.
- 00:27
PEMDAS tells us to work with the variables inside the parentheses first.
- 00:31
2a and 4a can't get any simpler...
- 00:33
...so we can move to the exponents.
- 00:35
We have the quantity 2a to the 4th, which means that we take 2 to the 4th...
- 00:40
...which is 16 times a to the 4th, so... 16a to the 4th.
- 00:46
Next we have the quantity 4a to the negative second.
- 00:49
Don't forget that little negative next to the 2 in the exponent.
- 00:53
Remember that negative exponents basically just mean "1 over."
- 00:57
We can move the 4a into the denominator and square it...which simplifies the fraction
- 01:02
as 1 over 16 times a squared.
- 01:05
When we multiply 16a to the 4th and one over 16 a-squared, we can cancel out the 16
- 01:10
over 16 to 1 over 1... or 1.
- 01:14
...and cancel the a to the 4th over a squared to a squared.
- 01:19
This leaves us with a squared... or the answer... which also happens to be A.
- 01:23
Now let's get out of here before Aunt Sally sets this whole place on fire.
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