Question

5 In nahiangle Bcm. Ireos B = / 13 which function also cauals

Answer 1

Given data:

The given measurement of angle C is 90 degrees.

The given value of cos(B) =5/13.

The sum of all angles of triangle is,

`\begin{gathered} \angle A+\angle B+\angle C=180^(\circ) \\ \angle A+\angle B+90^(\circ)=180^(\circ) \\ \angle A+\angle B=90^(\circ) \\ \angle B=90^(\circ)-\angle A \end{gathered}`

Substitute the above value in the given expression.

`\begin{gathered} \cos (90^(\circ)-A)=(5)/(13) \\ \sin A=(5)/(13) \end{gathered}`

Thus, the correct answer is sin(A), so the third option is correct.