=2(sin2xcosπ/6+cos2xsinπ/6)+1+a
=2sin(2x+π/6)+1+a
0<=x<=π/2
π/6<=2x+π/6<=7π/6
所以-1/2<=sin(2x+π/6)<=1
a<=f(x)<=3+a
-2
已知函数f(x)=2cos平方x加根号3sin2x加a,若x属于[0,2分之派],且|f(x)|小于2,求实数a的取值范围?急
已知函数f(x)=2cos平方x加根号3sin2x加a,若x属于[0,2分之派],且|f(x)|小于2,求实数a的取值范围?急
数学人气：257 ℃时间：2019-10-19 13:34:46
优质解答
f(x)=√3sin2x+cos2x+1+a
=2(sin2xcosπ/6+cos2xsinπ/6)+1+a
=2sin(2x+π/6)+1+a
0<=x<=π/2
π/6<=2x+π/6<=7π/6
所以-1/2<=sin(2x+π/6)<=1
a<=f(x)<=3+a
-2
=2(sin2xcosπ/6+cos2xsinπ/6)+1+a
=2sin(2x+π/6)+1+a
0<=x<=π/2
π/6<=2x+π/6<=7π/6
所以-1/2<=sin(2x+π/6)<=1
a<=f(x)<=3+a
-2
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