These angles are 'related angles' and their cosines and tangents will be related in a similar way. In the following diagrams, the sines, cosines and tangents of each of the shaded angles have the same magnitude (ø is the same angle in each diagram): The sines, cosines and tangents of some angles are equal to the sines, cosines and tangents of other angles. This is easy to remember, since it spells 'cast'. In the fourth quadrant, Cos is positive, in the first, All are positive, in the second, Sin is positive and in the fourth quadrant, Tan is positive. In the fourth quadrant, the values for cos are positive only. In the third quadrant, the values for tan are positive only. In the second quadrant, the values for sin are positive only. In the first quadrant, the values for sin, cos and tan are positive. The angles between 90º and 180º are in the second quadrant, angles between 180º and 270º are in the third quadrant and angles between 270º and 360º are in the fourth quadrant: The angles which lie between 0º and 90º are said to lie in the first quadrant. On a set of axes, angles are measured anti-clockwise from the positive x-axis. These occur frequently and need to be remembered. The sine, cosine and tangents of common angles:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |