I _______ with my parents when he rang me up yesterday afternoon. A. am shopping B. am shoping C. was shopping D. was shoping 答案:C
设f(x)=3x+3x-8,用二分法求方程3x+3x-8=0在x∈(1,2)内近似解的过程中得f(1)<0,f(1.5)>0,f(1.25)<0,则方程的根落在区间
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A.(1.25,1.5)
B.(1,1.25)
C.(1.5,2)
D.不能确定