= Solution
For $0<\theta<\pi/2$ and $\lambda>\sin2\theta$, the discriminant is strictly positive. The two roots have positive sum $\lambda/c^2$ and positive product $s^2/c^2$, so both roots are positive and distinct. Each gives exactly one positive $\alpha$ and hence a different <right stretch tensor>. If $\lambda\ne1$, neither tensor is the undeformed identity because its third diagonal entry is $\lambda$. Thus \b[two distinct deformed configurations are possible]. Excluding $\lambda=1$ removes the case in which one of the two configurations is the undeformed body; it is not needed just for positivity of the roots.
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