Concept:Use substitution to simplify the inverse cosecant expression, then apply integration by parts.Explanation:Let θ=tan−1(ax).Then tanθ=ax, so squaring gives x=atan2θ.Simplify the integrand:xa+x=atan2θa+atan2θ=tan2θ1+tan2θUsing 1+tan2θ=sec2θ, we get:tan2θsec2θ=sin2θ1=cscθHence cosec−1(xa+x)=θ.So the integral becomes:∫θdxUsing integration by parts:∫θdx=xθ−∫xdθSince x=atan2θ,∫θdx=aθtan2θ−a∫tan2θdθNow tan2θ=sec2θ−1, therefore:∫tan2θdθ=∫(sec2θ−1)dθ=tanθ−θThus:∫θdx=aθtan2θ−a(tanθ−θ)+C=aθtan2θ−atanθ+aθ+CAnswer:Option B: aθtan2θ−atanθ+aθ+C, where θ=tan−1(ax) and C is the constant of integration.