怎样将f（X）=sin2X+cos2x+2转换为同一个角的三角函数？求详细过程~~~

显示全部楼层 · 2012-1-2 10:09:19

f（X）=sin2X+cos2x+2=根号2【sin2x/根号2+cos2x/根号2]+2=根号2sin(2x+π/4)+2 一般地：asinx+bcosx=根号（a^2+b^2)sin(x+φ)这个公式叫辅助角公式，非常有用...

千问 · 2012-1-2 10:09:19

f（X）=sin2X+cos2x+2
=√2[(√2/2)*sin2x+(√2/2)*cos2x]+2
=√2(sin2xcos45°+cos2xsin45°)+2
=√2sin(2x+45°)+2...

千问 · 2012-1-2 10:09:19

不知道，有可能是这样吧f（X）=sin2X+cos2x+2
=√2[(√2/2)*sin2x+(√2/2)*cos2x]+2
=√2(sin2xcos45°+cos2xsin45°)+2
=√2sin(2x+45°)+2...

千问 · 2012-1-2 10:09:19

f（X）=sin2X+cos2x+2=根号2【sin2x/根号2+cos2x/根号2]+2 =√2sin(2x+45°)+2...