已知兩個正數(shù)a,b滿足a+b<=4,則下列各式中,恒正確的是______A.1/a+1/b>=1 B.1/(a^2+b^2)<=1/4
熱心網(wǎng)友
選A先把不等式轉(zhuǎn)化為a+b/ab,再根據(jù)已知條件a+b=1,也即是1/a+1/b=1,所以選A
熱心網(wǎng)友
A B
熱心網(wǎng)友
A
已知兩個正數(shù)a,b滿足a+b<=4,則下列各式中,恒正確的是______A.1/a+1/b>=1 B.1/(a^2+b^2)<=1/4
選A先把不等式轉(zhuǎn)化為a+b/ab,再根據(jù)已知條件a+b=1,也即是1/a+1/b=1,所以選A
A B
A