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SAT Math 2.3 Algebra and Functions 206 Views
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Description:
SAT Math 2.3 Algebra and Functions. Calculate this function.
Transcript
- 00:02
Here's your math-y shmoop du jour...
- 00:05
If f of x equals x squared minus x and g of x equals x minus 2,
- 00:11
what is g of f of negative 2?
- 00:16
And here are the potential answers...
- 00:20
So this problem just wants us to take two functions given,
Full Transcript
- 00:23
and use them to find g of f of x.
- 00:25
As always, we start with the innermost set of parentheses.
- 00:30
We know that f of x equals x squared minus x.
- 00:35
Since we first want to find f of negative 2, we can replace x with negative 2.
- 00:41
If we do that, we get negative 2 squared minus negative 2 equals
- 00:47
4 minus negative 2, which equals 4 plus 2, which is 6.
- 00:51
f of negative 2 equals 6. Since we can replace f of negative 2 with
- 00:56
just plain old 6, the problem simplifies to g of 6.
- 01:01
G of x is equal to x minus 2, and in this case, x is f of negative 2, or 6.
- 01:10
So you just take 6 minus 2 to get 4, and... we've got our solution.
- 01:15
C's our guy.
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