Let $A, B$ and $C$ are the angles of a plain triangle and $\tan\left(\dfrac{A}{2}\right)=\dfrac{1}{3},; \tan\left(\dfrac{B}{2}\right)=\dfrac{2}{3}$. Then $\tan\left(\dfrac{C}{2}\right)$ is equal to
If $\alpha, \beta; (\alpha \ne \beta)$ satisfies the equation $a\cos\theta + b\sin\theta = c$, then the value of $\tan\left(\dfrac{\alpha + \beta}{2}\right)$ is
Let $\frac{\sin(\theta-\alpha)}{\sin(\theta-\beta)}=\frac{a}{b},\ \frac{\cos(\theta-\alpha)}{\cos(\theta-\beta)}=\frac{c}{d}$. Then the value of $\cos(\alpha-\beta)$ equals
If $\sin(\alpha+\beta)=1,\ \sin(\alpha-\beta)=\frac{1}{2},\ \alpha,\beta\in\left[0,\frac{\pi}{2}\right]$ then the value of $\tan(\alpha+2\beta)\tan(2\alpha+\beta)$ is