Find approximate values: 1) √(25.3) 2) √(49.5) 3) (26)^(1/3) 4) (2.5)^(1/4)

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Understand the Problem

The question is asking to find approximate values for several mathematical expressions, including square roots and cube roots. It provides various mathematical problems that require evaluation.

Answer

1. $\sqrt{25.3} \approx 5.03$ 2. $\sqrt{49.5} \approx 7.0357$ 3. $(26)^{1/3} \approx 2.963$ 4. $(2.5)^{1/4} \approx 1.21$
Answer for screen readers
  1. $\sqrt{25.3} \approx 5.03$
  2. $\sqrt{49.5} \approx 7.0357$
  3. $(26)^{1/3} \approx 2.963$
  4. $(2.5)^{1/4} \approx 1.21$

Steps to Solve

  1. Approximate $\sqrt{25.3}$

To find $\sqrt{25.3}$, we can approximate it using $\sqrt{25}$ since $25.3$ is close to $25$.

We know: $$ \sqrt{25} = 5 $$

Using a small adjustment, we find: $$ \sqrt{25.3} \approx 5 + \frac{0.3}{2 \times 5} = 5 + 0.03 = 5.03 $$

  1. Approximate $\sqrt{49.5}$

Next, we approximate $\sqrt{49.5}$ using $\sqrt{49}$:

$$ \sqrt{49} = 7 $$

We can adjust it similarly: $$ \sqrt{49.5} \approx 7 + \frac{0.5}{2 \times 7} \approx 7 + 0.0357 \approx 7.0357 $$

  1. Approximate $(26)^{1/3}$

To find the cube root of $26$, we can use $\sqrt[3]{27}$ since $26$ is close to $27$:

$$ \sqrt[3]{27} = 3 $$

Using a small adjustment: $$ (26)^{1/3} \approx 3 - \frac{1}{3 \times 9} = 3 - \frac{1}{27} \approx 3 - 0.037 \approx 2.963 $$

  1. Approximate $(2.5)^{1/4}$

For $(2.5)^{1/4}$, we can use $(2)^{1/4}$ because $2.5$ is close to $2$:

$$ (2)^{1/4} \approx 1.19 $$

Using the same adjustment: $$ (2.5)^{1/4} \approx 1.19 + \text{small adjustment} $$

Given $(2.5-2)=0.5$: $$ \approx 1.19 + \frac{0.5}{4 \times (1.19^3)} \approx 1.19 + 0.02 \approx 1.21 $$

  1. $\sqrt{25.3} \approx 5.03$
  2. $\sqrt{49.5} \approx 7.0357$
  3. $(26)^{1/3} \approx 2.963$
  4. $(2.5)^{1/4} \approx 1.21$

More Information

These approximations provide a quick and efficient way to estimate square roots and cube roots of numbers that are not perfect squares or cubes. Using nearby perfect squares or cubes helps in making estimations easier.

Tips

  • Not checking how close the numbers are to perfect squares or cubes can lead to inaccurate approximations.
  • Forgetting to adjust for the small difference when estimating.

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