## What is a concave simple definition?

(Entry 1 of 2) 1 : hollowed or rounded inward like the inside of a bowl a concave lens. 2 : arched in : curving in —used of the side of a curve or surface on which neighboring normals to the curve or surface converge and on which lies the chord joining two neighboring points of the curve or surface.

### What is an example of a concave?

The front side of a spoon is curved inwards. Such a surface is called concave. The inside part of a bowl is also an example of a concave surface. For example, a dentist uses a concave mirror to view a relatively larger image of the teeth.

#### What is a concave shape?

Concave describes shapes that curve inward. The inside part of a bowl is a concave shape. A concave is a surface or a line that is curved inward. In geometry, it is a polygon with at least one interior angle greater than 180°.

**What is a regular concave?**

Polygons with congruent sides and angles are regular; all others are irregular. Polygons with all interior angles less than 180° are convex; if a polygon has at least one interior angle greater than 180°, it is concave.

**What does concave mean in economics?**

f is concave on [a, b] if and only if f”(x) ≤ 0 for all x ∈ (a, b). If f”(x) < 0 for all x ∈ (a,b) then f is strictly concave on [a, b], but the converse is not true: if f is strictly concave then its second derivative is not necessarily negative at all points. (Consider the function f(x) = −x4.

## What does convex mean in math?

A convex polygon is a closed figure where all its interior angles are less than 180° and the vertices are pointing outwards. The term convex is used to refer to a shape that has a curve or a protruding surface. In other words, all the lines across the outline are straight and they point outwards.

### Is a star convex or concave?

Is Star a Concave Polygon? Yes, a star is a concave polygon. Because concave polygon should have at least 4 sides. Also, one or more interior angles should be greater than 180 degrees.

#### What is convex vs concave?

Concave means “hollowed out or rounded inward” and is easily remembered because these surfaces “cave” in. The opposite is convex meaning “curved or rounded outward.” Both words have been around for centuries but are often mixed up. Advice in mirror may be closer than it appears.

**How do you define concave and convex?**

**Is a triangle concave?**

A triangle can never be concave, but there exist concave polygons with n sides for any n > 3. At least one interior angle does not contain all other vertices in its edges and interior. The convex hull of the concave polygon’s vertices, and that of its edges, contains points that are exterior to the polygon.

## When a function is concave?

A function of a single variable is concave if every line segment joining two points on its graph does not lie above the graph at any point. Symmetrically, a function of a single variable is convex if every line segment joining two points on its graph does not lie below the graph at any point.

### Is a square concave or convex?

A polygon in which all the interior angles are less than 180° is a convex polygon. Also in a square, all the vertices point outwards, which also makes it a convex shape. Therefore, a square is a convex polygon.