Spiral
A spiral is a curve that continuously approaches a central point, known as the origin or pole, while rotating around it. Spirals are found in various natural and man-made phenomena, and they can be described mathematically using polar coordinates. In polar coordinates, a spiral is defined by the equation r = aθ, where r is the radius, θ is the angle, and a is a constant that determines the rate of rotation. Spirals can be further classified into two main types: Archimedean spirals and logarithmic spirals. Archimedean spirals have a constant rate of rotation and are described by the equation r = aθ. Logarithmic spirals, also known as equiangular spirals, have a constant angle between the radius and the tangent at any point on the curve and are described by the equation r = ae^(bθ), where b is a constant. Spirals are commonly observed in nature, such as in the arrangement of leaves on a stem, the shape of seashells, and the pattern of galaxies. They are also used in various fields, including engineering, architecture, and art, for their aesthetic appeal and practical applications.