Fatou marks the points (3,-5) and (-2,-7) on the coordinate plane. Then, she finds the distance between them. What is this distance rounded up to the nearest tenth of a unit?

1 answer

To find the distance between the points \((3, -5)\) and \((-2, -7)\) on the coordinate plane, we can use the distance formula:

\[ d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \]

Here, \((x_1, y_1) = (3, -5)\) and \((x_2, y_2) = (-2, -7)\).

Now, substitute these values into the formula:

  1. Calculate \(x_2 - x_1\): \[ x_2 - x_1 = -2 - 3 = -5 \]

  2. Calculate \(y_2 - y_1\): \[ y_2 - y_1 = -7 - (-5) = -7 + 5 = -2 \]

  3. Now plug these values into the distance formula: \[ d = \sqrt{(-5)^2 + (-2)^2} \]

  4. Calculate \((-5)^2\) and \((-2)^2\): \[ (-5)^2 = 25 \quad \text{and} \quad (-2)^2 = 4 \]

  5. Add these results: \[ 25 + 4 = 29 \]

  6. Finally, take the square root: \[ d = \sqrt{29} \]

Next, we approximate \(\sqrt{29}\). The square root of 29 falls between the perfect squares of 25 and 36:

\[ 5^2 = 25 \quad \text{and} \quad 6^2 = 36 \]

Calculating a more precise value, we find:

\[ \sqrt{29} \approx 5.385 \]

Rounding this to the nearest tenth, we get:

\[ \sqrt{29} \approx 5.4 \]

Thus, the distance between the points \((3, -5)\) and \((-2, -7)\) rounded up to the nearest tenth of a unit is:

\[ \boxed{5.4} \]