√3 cos40°+sin40°/sin40°cos40°
1个回答

是(√3 cos40°+sin40°)/(sin40°cos40°)吧?

如果是的话:

(√3 cos40°+sin40°)/(sin40°cos40°)

=2{[(√3)/2]cos40°+(1/2)sin40°}/[(sin80°)/2]

=4(sin60°cos40°+cos60°sin40°)/sin80°

=4sin100°/sin80°

=4sin(90°+10°)/sin(90°-10°)

=4cos10°/cos10°

=4