f(x)=cos^2x+sinx=1-sin^2x+sinx=-(sinx-1/2)^2+5/4∵x∈[-π/4,π/4]∴sinx∈[-√2/2,√2/2]∵对称轴为sinx=1/2当sinx=-√2/2,即x=-π/4时（离对称轴较远）f(x)取得最小值：cos^2(-π/4)+sin(-π/4)=1/2-√2/2希望...