. . . . . . . "0"^^ . . . "06670390-n"^^ . . . "biquadratic equation"^^ . . . "106260051"@en-us . "0"^^ . . "106670390"^^ . . "biquadratic equation"@en-us . "an equation of the fourth degree"@en-us . . . . . . "biquadratic"@en-us .