In the SABR model, suppose that $F_0=5, \beta=0.5, \sigma_0=0.447$ (equivalent to a lognormal volatility of $20 \%$ ), and $T=1$. Show how the volatility smile varies with $\rho$ for (a) $v=0.6$ and (b) $v=1.2$. Consider value of $\rho$ equal to $0.4,0.2,0,-0.2,-0.4$ and values of the strike price equal to $4.0,4.5,5.0,5.5,6.0$.