To find the coordinates of point B we need to notice that this points is on the quarter of a circle shown in the picture. This circle have radius one.
Now, from the definitions of the sine ans cosine function we conclude that for point B(x,y):
![\begin{gathered} x=\sin 45=\frac{\sqrt[]{2}}{2} \\ y=\cos 45=\frac{\sqrt[]{2}}{2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/xd34vl5lak6mksa87wkrbup0hej1zyp5do.png)
Therefore the coordinates of the point B are:
![B(\frac{\sqrt[]{2}}{2},\frac{\sqrt[]{2}}{2})](https://img.qammunity.org/2023/formulas/mathematics/college/5xi0md0y6reegs4m831b0t0wrtzh2614hl.png)