Answer:
3⁰ = 1
x⁰ = 1
Explanation:
You want powers of 3 filled in your table from an exponent of 4 down to an exponent of 0.
Powers of 3
3⁴ = 3·3·3·3 = 81 . . . . . . 3 is a factor 4 times
3³ = 3·3·3 = 27 . . . . . . . 3 is a factor 3 times
Each row of the table has 3 being a factor of 3^x one fewer times, so each value of 3^x is 1/3 of the previous value.
The last two rows of the table are ...
3¹ = 3
3⁰ = 1
See the attachment for the whole table.
In general, the meaning of x⁰ is ...
x⁰ = 1
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Additional comment
In algebra, 0⁰ = 1 is the usual definition. In some contexts (mathematical analysis, calculus), it may be "undefined."
That means x⁰ = 1 for all real numbers x, including x = 0.