Express The Following Using A Positive Exponent, Then Simplify The Expression.$3^{-3}$Write Using A Positive Exponent. Do Not Evaluate.$3^{-3} = \square$

by ADMIN 154 views

**Expressing Negative Exponents: A Comprehensive Guide** =====================================================

What is a Negative Exponent?

A negative exponent is a mathematical expression that represents a number raised to a power that is less than zero. In other words, it is the reciprocal of a positive exponent. For example, 3−33^{-3} can be read as "3 to the power of negative 3" or "the reciprocal of 3 to the power of 3".

Expressing Negative Exponents using Positive Exponents

To express a negative exponent using a positive exponent, we can use the following rule:

a−n=1ana^{-n} = \frac{1}{a^n}

where aa is a non-zero number and nn is a positive integer.

Example: Expressing 3−33^{-3} using a Positive Exponent

Using the rule above, we can express 3−33^{-3} as:

3−3=1333^{-3} = \frac{1}{3^3}

Simplifying the Expression

To simplify the expression, we can evaluate the exponent:

33=3×3×3=273^3 = 3 \times 3 \times 3 = 27

So, the simplified expression is:

3−3=1273^{-3} = \frac{1}{27}

Q&A: Expressing Negative Exponents

Q: What is the rule for expressing negative exponents using positive exponents?

A: The rule is a−n=1ana^{-n} = \frac{1}{a^n}, where aa is a non-zero number and nn is a positive integer.

Q: How do I express 2−42^{-4} using a positive exponent?

A: Using the rule above, we can express 2−42^{-4} as:

2−4=1242^{-4} = \frac{1}{2^4}

Q: What is the simplified expression for 2−42^{-4}?

A: To simplify the expression, we can evaluate the exponent:

24=2×2×2×2=162^4 = 2 \times 2 \times 2 \times 2 = 16

So, the simplified expression is:

2−4=1162^{-4} = \frac{1}{16}

Q: Can I express a negative exponent using a positive exponent if the base is zero?

A: No, you cannot express a negative exponent using a positive exponent if the base is zero. The rule only applies to non-zero bases.

Q: How do I express x−2x^{-2} using a positive exponent?

A: Using the rule above, we can express x−2x^{-2} as:

x−2=1x2x^{-2} = \frac{1}{x^2}

Q: What is the simplified expression for x−2x^{-2}?

A: To simplify the expression, we can leave it as is, since x2x^2 is already a positive exponent.

Q: Can I express a negative exponent using a positive exponent if the exponent is a fraction?

A: Yes, you can express a negative exponent using a positive exponent if the exponent is a fraction. For example:

x−12=1x12x^{-\frac{1}{2}} = \frac{1}{x^{\frac{1}{2}}}

Q: How do I express y−13y^{-\frac{1}{3}} using a positive exponent?

A: Using the rule above, we can express y−13y^{-\frac{1}{3}} as:

y−13=1y13y^{-\frac{1}{3}} = \frac{1}{y^{\frac{1}{3}}}

Q: What is the simplified expression for y−13y^{-\frac{1}{3}}?

A: To simplify the expression, we can leave it as is, since y13y^{\frac{1}{3}} is already a positive exponent.

Conclusion

Expressing negative exponents using positive exponents is a useful technique in mathematics. By using the rule a−n=1ana^{-n} = \frac{1}{a^n}, we can simplify expressions and make them easier to work with. Remember to always evaluate the exponent and simplify the expression to get the final answer.