sin40°*(1-sin10°)/[sin10°*(cos20°)^2]
来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/28 02:51:59
sin40°*(1-sin10°)/[sin10°*(cos20°)^2]
2*根号3
2*根号3
sin40°(1-sin10°)/[sin10°(cos20°)^2]
=2sin20°cos20°(1-cos80°)/ [sin10°(cos20°)^2]
=2sin20°(sin40°)^2/(sin10°cos20°)
=2sin20°(2cos20°sin20°)^2/(sin10°cos20°)
=16cos10°cos20°(sin20°)^3/(2sin10°cos10°)
=16cos10°cos20°(sin20°)^2
=8sin80°sin40°sin20°
=4(cos40°-cos120°)sin20°
=4(cos40°sin20°+1/2sin20°)
=4(1/2sin60°-1/2sin20°+1/2sin20°)
=4sin60°
=2√3
=2sin20°cos20°(1-cos80°)/ [sin10°(cos20°)^2]
=2sin20°(sin40°)^2/(sin10°cos20°)
=2sin20°(2cos20°sin20°)^2/(sin10°cos20°)
=16cos10°cos20°(sin20°)^3/(2sin10°cos10°)
=16cos10°cos20°(sin20°)^2
=8sin80°sin40°sin20°
=4(cos40°-cos120°)sin20°
=4(cos40°sin20°+1/2sin20°)
=4(1/2sin60°-1/2sin20°+1/2sin20°)
=4sin60°
=2√3
sin40°*(1-sin10°)/[sin10°*(cos20°)^2]
sin10°^2+cos40°^2+sin10°sin40°
cos20°cos10°+sin10°sin10°
化简[2sin50°+sin10°(1+3tan10°)]1+cos20°
sin40°cos10°-cos40°sin10°
求 3/(cos80°×sin40°)--1/(sin10°×cos40°) 的值
求 3/(cos80°×sin40°平方)--1/(sin10°×cos40°平方) 的值
化简((cos20°/sin20°)cos10°)+根号3(sin10°tan70°)-2cos40°
化简{2sin50°+sin10°【1+(根号3tan10°)】根号(1加cos20)°
cos20/(cos10+sin10)+sin10
[2sin50°+sin10°(1+根号3tan10°)]乘sin10°等于?
化简1−2sin10°cos10°sin10°−1−sin