[R] Finding determinants of x-loaded matrix?

R friends, I need to find the determinant of this matrix x 1 0 0 1 x 1 0 0 1 x 1 0 0 1 x det yields x^4-3x^2+1 I can then use polyroot to find the roots of the coefficients. The question is about the use of "x", which is what I'm solving for. thanks in advance, and this is a back-burner ques

[R] Singularity in a regression?

R friends, In a matrix of 1s and 0s, I'm getting a singularity error. Any helpful ideas? lm(formula = activity ~ metaF + metaCl + metaBr + metaI + metaMe + paraF + paraCl + paraBr + paraI + paraMe) Residuals: Min 1Q Median 3QMax -4.573e-01 -7.884e-02 3.4