Question

Prove that: please do it fast​

Answer 1

Answer:

Step-by-step explanation:

$A+B=\theta\\B=\theta-A\\sin B=sin (\theta-A)\\sin A=\lambda[sin \theta cos A-cos \theta sin A]\\sin A[1+\lambda cos \theta]=cos A(\lambda sin \theta) \\\frac{sin A}{cosA} =\frac{\lambda sin \theta}{1+ \lambda cos \theta}$

$tan A=\frac{\lambda sin \theta }{1+ \lambda cos \theta }$