The factorial of the number 0 is defined as 1 because there is only one possible permutation for a set of zero elements, namely the empty set. The combinatorial interpretation of the factorial function is the total number of possible permutations of a set of n elements.
A permutation can also be defined, in this case, as a way of arranging the objects in question. The factorial function "n!" of a positive integer n is defined as the product of all the positive integers smaller than or equal to n. It can be recursively defined as "n! = n × (n ? 1)!," where 0! and 1! are known to have the value of 1.
Learn MoreIn geometry, a plane is defined as a flat, infinite surface. It has infinite length and width but no thickness. A plane is thus a two-dimensional, boundless surface and a subset of space.
Full Answer >The incenter of a triangle is defined as the point where all three angle bisectors intersect. It can be found using a compass and a straight edge by constructing the angle bisectors of any two vertices of the triangle and marking the point where they cross. Two angle bisectors are sufficient to define the point where all three intersect, so the third angle bisector need not be drawn.
Full Answer >In geometry, a vertex is defined as a point where two or more lines meet. A triangle has three vertices. A parallelogram has four vertices. A six-sided figure has six vertices. A pentagon is a five-sided figure and has five vertices.
Full Answer >The diameter of a circle is defined as a segment drawn through the center, touching two points on the perimeter. The length of the diameter is the same, even when changing the location of the two points.
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