To find the angle of elevation between the board and the lower side of the ditch using the inverse sine function, we can set up the problem using the given dimensions.
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Identify the sides of the triangle:
- The length of the board (hypotenuse) = 6 feet.
- The vertical height (opposite side) = 3 feet (the difference in height between the two sides of the ditch).
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Use the sine definition: The sine of an angle is defined as the ratio of the length of the opposite side to the length of the hypotenuse: \[ \sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{3}{6} = \frac{1}{2} \]
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Find the angle using the inverse sine: To find the angle \(\theta\), we take the inverse sine (or arcsin) of \(1/2\): \[ \theta = \sin^{-1}\left(\frac{1}{2}\right) \]
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Calculate the angle: The angle whose sine is \(1/2\) is \(30^\circ\).
Therefore, the approximate angle of elevation formed between the board and the lower side of the ditch is 30 degrees.