What is f(-2) when f(x) = x^2 - 4x?
f(x) is a rule with a name, not multiplication. f(-2) means: feed -2 into the rule and see what comes out.
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2 lessons for “Function notation”
Which x values are allowed in f(x) = 1/(x - 2)?
A function's domain is the list of numbers you may feed it. A zero denominator is one number that is never allowed.
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What equation undoes f(x) = 2x + 3?
An inverse function undoes whatever the original did. Here f multiplies by 2 and adds 3, so the inverse must unwind both in reverse.
Try this lessonWhere does the decimal point go?
Evan wrote 4500 as 4.5 * 10^4. He counted the digits instead of the decimal jumps.
Try this lessonWhich organelle makes the cell's energy?
You said the nucleus makes the cell's energy. The instructions live in the nucleus, but the energy-making has a different address.
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