Powers Of 4
1. **State the problem:** Write each expression as a single power of 4.
2. **Recall:**
- $\sqrt{a} = a^{1/2}$
- $\sqrt[n]{a} = a^{1/n}$
3. **Solve each part:**
**a) $(\sqrt{16})^3$**
- First, rewrite $\sqrt{16} = 16^{1/2}$.
- Since $16 = 4^2$, then $16^{1/2} = (4^2)^{1/2} = 4^{2 \times \frac{1}{2}} = 4^1 = 4$.
- Now raise it to the power 3: $(4)^3 = 4^3$.
- **Answer:** $4^3$.
**b) $\sqrt[3]{16}$**
- Rewrite as $16^{1/3}$.
- Substitute $16 = 4^2$ so $16^{1/3} = (4^2)^{1/3} = 4^{2/3}$.
- **Answer:** $4^{2/3}$.
**c) $\sqrt{64} \times (\sqrt[4]{128})^3$**
- Rewrite $\sqrt{64} = 64^{1/2}$ and $\sqrt[4]{128} = 128^{1/4}$.
- Express $64$ and $128$ as powers of 4:
- $64 = 4^3$ (since $4^3 = 64$)
- $128 = 2^7 = (4^{1/2})^7 = 4^{7/2}$
- So,
- $64^{1/2} = (4^3)^{1/2} = 4^{3/2}$
- $(128^{1/4})^3 = (4^{7/2})^{1/4 \times 3} = 4^{\frac{7}{2} \times \frac{3}{4}} = 4^{21/8}$
- Multiply powers of 4: $4^{3/2} \times 4^{21/8} = 4^{\frac{3}{2} + \frac{21}{8}} = 4^{\frac{12}{8} + \frac{21}{8}} = 4^{33/8}$.
- **Answer:** $4^{33/8}$.
**d) $(\sqrt{2})^8 \times (\sqrt[3]{2})^4$**
- Rewrite:
- $\sqrt{2} = 2^{1/2}$ so $(\sqrt{2})^8 = (2^{1/2})^8 = 2^{8/2} = 2^4$
- $\sqrt[3]{2} = 2^{1/3}$ so $(\sqrt[3]{2})^4 = (2^{1/3})^4 = 2^{4/3}$
- Multiply powers of 2: $2^4 \times 2^{4/3} = 2^{4 + 4/3} = 2^{\frac{12}{3} + \frac{4}{3}} = 2^{16/3}$
- Now express base 2 as power of 4: since $2 = 4^{1/2}$,
$$2^{16/3} = (4^{1/2})^{16/3} = 4^{\frac{1}{2} \times \frac{16}{3}} = 4^{8/3}$$
- **Answer:** $4^{8/3}$.
**Final answers:**
**a)** $4^3$
**b)** $4^{2/3}$
**c)** $4^{33/8}$
**d)** $4^{8/3}$