The focal length of ellipse {x = 4 + 2cos θ, y = 2Sin θ (θ is a parameter) is

The focal length of ellipse {x = 4 + 2cos θ, y = 2Sin θ (θ is a parameter) is

It's a circle, not an ellipse
Brother, are you an ellipse? Are you a circle
The parameter equation is (y + 2) = 4
Is a circle with a radius of 2 and a center at (4,0)
(if it has to be an ellipse, the two focal points coincide at the center of the circle, and the focal length is 0)
The ordinary equation of parameter equation x = 3sin @ y = 2cos @ of ellipse
From x = 3sin θ, y = 2cos θ, it is obtained that: 1
sinθ＝x/3,cosθ＝y/2,
And (sin θ) ^ 2 + (COS θ) ^ 2 = 1,
∴(x/3)^2＋(y/2)^2＝1,
That is, x ^ 2 / 9 + y ^ 2 / 4 = 1,
This is the ordinary equation of ellipse
Four seven, no matter add subtract multiply divide, how equal to 7?
(7-7)*7+7=7
The previous equation is equal to 0, and then 0 + 7 is equal to 7 ~ I don't know if I'm satisfied ~ ~!
Xiao Hong's mother works four days and has one day off. Xiao Hong's father works two days and has one day off. Xiao Hong has two days off on Saturdays and Sundays,
Xiao Hong, my father and mother have a rest on the 2nd. They go to see my grandfather together. They are going to visit the museum on the next day when they have a rest at the same time. When is the day to visit the museum?
4+1=5 2+3=5 5+1=6 5X3X6=90 4+1=5 2+1=3 5+2=7 5X3X7=105
105-90 = 15 + 2 = 17