Question

Using the property of determinants and without expanding, prove that: x a x+ a =|y b y + b|=0z c z+ c

1. Why  equn 03  why not equn 1*3
   
2. Make it easier please 

Principle value of cosec-1(x)

Integration sec^2x/a+btanx

In figure PQ and PR are two mirror which are joined at Qat angle of 30 to each other. If incident ray AB is parallel to mirror RC, then find the values of Angle BCQ, angle CBQ, angle BDC