Triangle related question

In a triangle PQR , angle R=pi/2 .It tan(P/2)and tan(Q/2) are the roots of the equation $ ax^2+bx+c=0,(a\ne0) $, then
a)a+b=c
b)b+c=a
c)a+c=b
d)b=c

Comments

answer

$ \frac{P}{2}=u;\:\frac{Q}{2}=v $

$$u+v=\frac{\pi}{4}$$
$$\tan(u+v)=\frac{\tan u+\tan v}{1-\tan u\tan v}=1$$
$$\tan u+\tan v=1-\tan u\tan v$$
$$-\frac{b}{a}=1-\frac{c}{a}$$
$$a+b=c$$

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