12题……过程?
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/06 22:04:19
![12题……过程?](/uploads/image/z/6999813-45-3.jpg?t=12%E9%A2%98%E2%80%A6%E2%80%A6%E8%BF%87%E7%A8%8B%3F)
xJ@E*LL4d&v*VWىtW"Ν+Z_8i
ܹA&0,z
Ap(/E{5qicot"'Qh%idLx'-yQNb܀1ioE!Pv%VErXr)O0S)}GJR,J%%rE2++c.ъd#fS_Z܊B.mGsۨ%joVԚӦ-Qcc6&f, |zWL&e~]6V*d! |̊Nt
_-Ճ
12题……过程?
12题……过程?
12题……过程?
y=cos^2x-3sinx+2
=1-sin^2x-3sinx+2
=-(sin^2x+3sinx)+3
=-(sin^2x+3sinx+9/4)+3+9/4
=-(sinx+3/2)^2+21/4
最大值是当sinx=-1时
y最大=-(-1+3/2)^2+21/4
=-1/4+21/4
=5
选C