In , is the median to side . The median makes an angle with side and an angle with…

MATHEMATICS · Subjective · A Level · Mathematics · Trigonometry · Trigonometry

Problem

\triangle ABC

AD

is the median to side

BC

. The median

AD

makes an angle

\theta

with side

AB

and an angle

\phi

with side

AC

. Let

c

denote the length of side

AB

and

b

the length of side

AC

. Prove that

\frac{\sin \theta}{\sin \phi} = \frac{c}{b}.