√[6²-(2+√14)²]
=√[6²-(4+4√14+14)]
=√[36-(4+4√14+14)]
=√[18-4√14]
=√[14-4√14+4]
=√[√14²-4√14+2²]
=√(√14-2)²
=√14-2
结果是√14-2