令a=根号15+x^2b=根号19-x^2则a^2=15+x^2,x^2=a^2-15b^2=19-x^2,x^2=19-b^2所以x^2=a^2-15=19-b^2a^2+b^2=34a-b=2等式平方a^2+b^2-2ab=4ab=[(a^2+b^2)-4]/2=(34-4)/2=15所以a^2b^2=225(x^2+15)(19-x^2)=225-x^4+4x^2...