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Algebra and Functions Videos 140 videos

SAT Math 1.2 Algebra and Functions
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SAT Math: Algebra and Functions Drill 1, Problem 2. Based on the data in the table, what is the maximum heart rate for the average 22-year-old?

SAT Math 1.3 Algebra and Functions
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SAT Math 1.3 Algebra and Functions. How many 16 oz. bottles did she buy?

SAT Math 1.4 Algebra and Functions
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SAT Math 1.4 Algebra and Functions. Solve for x.

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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.

Language:
English Language

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,

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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