When you rotate a quarter circle about the x-axis, you create a three-dimensional shape known as a circular cone. The quarter circle is defined in the first quadrant of the coordinate plane, bounded by the x-axis and y-axis.
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Quarter circle definition: The quarter circle has a radius \( r \) and is part of the circle defined by the equation \( x^2 + y^2 = r^2 \), for \( x \geq 0 \) and \( y \geq 0 \).
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Rotation: When this quarter circle is rotated about the x-axis, every point on the curve sweeps out a surface in three-dimensional space. The resulting shape has a circular cross-section perpendicular to the x-axis at any point.
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Resulting shape: The resulting solid is a cone with its apex at the origin (0,0,0) and its base on the plane perpendicular to the x-axis at \( x = r \).
So, the object formed by rotating a quarter circle about the x-axis is a circular cone.