若√a-1+√ab -2=0,求1/ab+1/(a+1)(b+1)+...1/(a+2009)(b+2009)
问题描述:
若√a-1+√ab -2=0,求1/ab+1/(a+1)(b+1)+...1/(a+2009)(b+2009)
答
是√a -1 + √ab -2=0 还是 √(a-1)+√(ab -2) =0?若是 √(a-1)+√(ab -2) =0,则有a-1=0,ab-2=0,所以a=1,b=2所以,1/ab+1/(a+1)(b+1)+...1/(a+2009)(b+2009)=1/1*2 + 1/2*3 + 1/3*4 +……+ 1/2010*20...我是说是√a-1 + √ab -2=0你的意思是说√a+ √ab =3 吗?不是,是√a-1+√ab-2 (空格)-2=0