12.已知函数f(x)=$\left\{{\begin{array}{l}{lnx,x>0}\\{{x^2}+3x-3,x≤0}\end{array}}$,则函数零点的个数为( )
| A. | 0 | B. | 1 | C. | 2 | D. | 3 |
10.已知函数f(x)=x3+ax2+bx+a2在x=1处有极值为10,则(a,b)的值( )
| A. | (4,-11) | B. | (-3,3) | C. | (4,-11)或(-3,3) | D. | 不存在 |
9.已知函数f(x)满足f(x)=f(π-x),且当x∈(-$\frac{π}{2}$,$\frac{π}{2}$)时,f(x)=ex+sinx,则( )
0 234853 234861 234867 234871 234877 234879 234883 234889 234891 234897 234903 234907 234909 234913 234919 234921 234927 234931 234933 234937 234939 234943 234945 234947 234948 234949 234951 234952 234953 234955 234957 234961 234963 234967 234969 234973 234979 234981 234987 234991 234993 234997 235003 235009 235011 235017 235021 235023 235029 235033 235039 235047 266669
| A. | $f(\frac{π}{3})<f(\frac{π}{4})<f(\frac{5π}{6})$ | B. | $f(\frac{π}{4})<f(\frac{π}{3})<f(\frac{5π}{6})$ | C. | $f(\frac{π}{4})<f(\frac{5π}{6})<f(\frac{π}{3})$ | D. | $f(\frac{5π}{6})<f(\frac{π}{4})<f(\frac{π}{3})$ |