CN201838225U

CN201838225U - Multi-purpose ruler

Info

Publication number: CN201838225U
Application number: CN2009202822556U
Authority: CN
Inventors: 孙玉东
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-27
Filing date: 2009-11-27
Publication date: 2011-05-18
Anticipated expiration: 2019-11-27

Abstract

The utility model relates to a math teaching aid, in particular to a multi-purpose ruler which can look up four direct trigonometric functions and anti-trigonometric functions, namely sine, cosine, tangent and cotangent. The multi-purpose ruler is provided with a round bottom plate (1), and angle ruling values between 0-360 degrees are arranged at the edge of the bottom plate (1); the bottom plate is drawn with a unit circle, a rectangular coordinate system and a straight line which is parallel to an X axis and a Y axis, and tangential to the unit circle; and the original point of the rectangular coordinate system is coincident with the center of the unit circle. The multi-purpose ruler is characterized in that a rotary long pointer is connected at the circle of the center on the back surface of the bottom plate, and the other end of the pointer is connected in a through groove on a vertical rod by a screw when being folded towards the front surface so as to reach the unit circle, the vertical rod with scales is connected with a trapezoidal block, and the vertical rod is divided into two equal parts by taking the fixing point as the boundary, and the trapezoidal block is matched and connected with a groove at the X coordinate axis on the bottom plate.

Description

A kind of multipurpose ruler

Technical field

The utility model relates to a kind of teaching aid, specifically is a kind of multipurpose ruler of learning trigonometric function.

Background technology

Existing this type of trigonometric function plate teaching aid in present teaching, complex structure, insufficiency, use inconvenience; The purpose of this utility model is to avoid above-mentioned prior art weak point and a kind of trigonometric function teaching ruler of providing, it can just found quickly and accurately, cosine and just, four positive and negative trigonometric function values of cotangent.

Summary of the invention

This practical new purpose provides a kind of can just finding quickly and accurately, cosine and just, the instrument of four positive inverse trigonometric function of cotangent, its technical scheme is: a kind of multipurpose ruler, circular bottom plate is arranged, indicate the angle index value of 0-360 degree at its marginal belt, on base plate, be painted with unit circle, rectangular coordinate system and and X, the straight line that Y-axis is parallel and tangent with unit circle, the initial point of rectangular coordinate system overlaps with the center of circle of unit circle, it is characterized in that: have a rotating Long pointer to be connected in the circle centre position at the base plate back side, this pointer other end is folded to the front at the bottom edge place, be connected in the groove on the montant by screw during to unit circle, graduated montant and trapezoid block are fixed together, as the boundary, montant is split equal two parts, and trapezoid block flexibly connects with axle.

The beneficial effects of the utility model are: simple structure, operate easily, the value of looking into is accurate.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Circular bottom plate 1, Long pointer 2, groove 3, trapezoid block 4, axle 5 are arranged among the figure.

Embodiment

Referring to last figure, the utility model is a kind of multipurpose ruler, circular bottom plate is arranged, indicate the angle index value of 0-360 degree at its marginal belt, on base plate, be painted with unit circle, rectangular coordinate system and and X, the straight line that Y-axis is parallel and tangent with unit circle, the initial point of rectangular coordinate system overlaps with the center of circle of unit circle, it is characterized in that: have a rotating Long pointer to be connected in the circle centre position at the base plate back side, this pointer other end is folded to the front at the bottom edge place, be connected in the groove on the montant by screw during to unit circle, graduated montant and trapezoid block are fixed together, as the boundary, montant is split equal two parts, and trapezoid block flexibly connects with axle.

The utility model can be made teaching aid, looks into positive and negative trigonometric function value; The trigonometric function value at special angle obviously marks on the function plate, is convenient to students ' understanding, memory; By pointer rotation, montant translation, the student can be by observing and thinking the visual in image teaching of carrying out trigonometric function and study, the variation relation of help student understanding and grasp angle and function value in each quadrant.The utility model simple structure, operate easily, the value of looking into is accurate.

Claims

1. multipurpose ruler, circular bottom plate (1) is arranged, indicate the angle index value of 0-360 degree at its marginal belt, on base plate, be painted with unit circle, rectangular coordinate system and and X, the straight line that Y-axis is parallel and tangent with unit circle, the initial point of rectangular coordinate system overlaps with the center of circle of unit circle, it is characterized in that: have a rotating Long pointer (2) to be connected in the circle centre position at the base plate back side, this pointer other end is folded to the front at the bottom edge place, be connected in the groove (3) on the montant by screw during to unit circle, graduated montant and trapezoid block (4) are fixed together, as the boundary, montant is split equal two parts, and trapezoid block (4) flexibly connects with axle (5).