509,261 views
9 votes
9 votes
In the accompanying diagram of circle O, COA is adiameter, O is the origin, OA = 1, and mLBOA = 30. Whatare the coordinates of B?

In the accompanying diagram of circle O, COA is adiameter, O is the origin, OA = 1, and-example-1
User Kampu
by
2.9k points

1 Answer

18 votes
18 votes

Given:

COA is a diameter

O is the origin

OA = 1

m< BOA = 30

Re-drawing the diagram to show the coordinates of the B:

Let the coordinates of B be (x,y)

Using trigonometric ratio, we can find the length of side AB

From trigonometric ratio, we have:


tan\text{ }\theta\text{ = }(opposite)/(adjacent)

Substituting we have:


\begin{gathered} tan\text{ 30 = }(y)/(1) \\ Cross-Multiply \\ y\text{ = tan30 }*\text{ 1} \\ y\text{ = 0.577} \\ y\text{ }\approx\text{ 0.58} \end{gathered}

Hence, the coordinates of B is (1, 0.58)

In the accompanying diagram of circle O, COA is adiameter, O is the origin, OA = 1, and-example-1
User Corey
by
2.7k points