Test case -- Rootsolver (second example):

The error for root 0.0499999992458867 = -0.0000000000028057
The error for root 0.2399999995241274 = 0.0000000000000774
The error for root 0.3899999900567189 = -0.0000000000001383
The error for root 0.5400000082790142 = 0.0000000000000249
The error for root 0.7200000001690509 = 0.0000000000000009
The error for root 0.4799993782338083 = 0.0000000000022229
The error for root 0.6599999717868444 = 0.0000000000001024
The error for root 0.9300000000000354 = 0.0000000000000000
The error for root 0.8100001316985610 = -0.0000000000034587
