早教吧作业答案频道 -->数学-->
曲线x=t−sinty=1−cost在t=π2处的曲率半径R=2222.
题目详情
|
π |
2 |
2
2 |
2
.2 |
|
x=t−sint |
y=1−cost |
x=t−sint |
y=1−cost |
x=t−sint |
y=1−cost |
π |
2 |
2
2 |
2
.2 |
π |
2 |
2
2 |
2 |
2 |
2
2 |
2 |
2 |
▼优质解答
答案和解析
利用曲率的计算公式可得,
K(x)=
=|
|.
因为
=
=
,
=
=−
,
代入曲率的计算公式可得,
R=
=
=2
.
将t=
代入可得,
R=
1 1 1R R R=|
y″ y″ y″(1+y′2)
(1+y′2)
(1+y′2)
2)
3 3 32 2 2|.
因为
=
=
,
=
=−
,
代入曲率的计算公式可得,
R=
=
=2
.
将t=
代入可得,
R=
dy dy dydx dx dx=
dy dy dydt dt dt
dx dx dxdt dt dt=
sint sint sint1−cost 1−cost 1−cost,
=
=−
,
代入曲率的计算公式可得,
R=
=
=2
.
将t=
代入可得,
R=
d2y d2y d2y2ydx2 dx2 dx22=
(
)t (
)t (
dy dy dydx dx dx)tt
dx dx dxdt dt dt=−
1 1 1(1−cost)2 (1−cost)2 (1−cost)22,
代入曲率的计算公式可得,
R=
=
=2
.
将t=
代入可得,
R=
(1+(
)2)
(1+(
)2)
(1+(
dy dy dydx dx dx)2)
2)
3 3 32 2 2|
| |
| |
d2y d2y d2y2ydx2 dx2 dx22|
=
=2
.
将t=
代入可得,
R=
(1+
)
(1+
)
(1+
sin2t sin2t sin2t2t(1−cost)2 (1−cost)2 (1−cost)22)
3 3 32 2 2
1 1 1(1−cost)2 (1−cost)2 (1−cost)22
=2
.
将t=
代入可得,
R= 2
2 2 2
.
将t=
代入可得,
R=
1−cost 1−cost 1−cost.
将t=
代入可得,
R=
π π π2 2 2代入可得,
R=
K(x)=
1 |
R |
y″ | ||
(1+y′2)
|
因为
dy |
dx |
| ||
|
sint |
1−cost |
d2y |
dx2 |
(
| ||
|
1 |
(1−cost)2 |
代入曲率的计算公式可得,
R=
(1+(
| ||||
|
|
=
(1+
| ||||
|
=2
2 |
1−cost |
将t=
π |
2 |
R=
1 |
R |
y″ | ||
(1+y′2)
|
3 |
2 |
3 |
2 |
3 |
2 |
3 |
2 |
3 |
2 |
因为
dy |
dx |
| ||
|
sint |
1−cost |
d2y |
dx2 |
(
| ||
|
1 |
(1−cost)2 |
代入曲率的计算公式可得,
R=
(1+(
| ||||
|
|
=
(1+
| ||||
|
=2
2 |
1−cost |
将t=
π |
2 |
R=
dy |
dx |
| ||
|
dy |
dt |
dy |
dt |
dy |
dt |
dx |
dt |
dx |
dt |
dx |
dt |
sint |
1−cost |
d2y |
dx2 |
(
| ||
|
1 |
(1−cost)2 |
代入曲率的计算公式可得,
R=
(1+(
| ||||
|
|
=
(1+
| ||||
|
=2
2 |
1−cost |
将t=
π |
2 |
R=
d2y |
dx2 |
(
| ||
|
dy |
dx |
dy |
dx |
dy |
dx |
dx |
dt |
dx |
dt |
dx |
dt |
1 |
(1−cost)2 |
代入曲率的计算公式可得,
R=
(1+(
| ||||
|
|
=
(1+
| ||||
|
=2
2 |
1−cost |
将t=
π |
2 |
R=
(1+(
| ||||
|
|
dy |
dx |
3 |
2 |
dy |
dx |
3 |
2 |
dy |
dx |
3 |
2 |
3 |
2 |
3 |
2 |
d2y |
dx2 |
d2y |
dx2 |
d2y |
dx2 |
=
(1+
| ||||
|
=2
2 |
1−cost |
将t=
π |
2 |
R=
(1+
| ||||
|
sin2t |
(1−cost)2 |
3 |
2 |
sin2t |
(1−cost)2 |
3 |
2 |
sin2t |
(1−cost)2 |
3 |
2 |
3 |
2 |
1 |
(1−cost)2 |
1 |
(1−cost)2 |
1 |
(1−cost)2 |
=2
2 |
1−cost |
将t=
π |
2 |
R= 2
2 |
1−cost |
将t=
π |
2 |
R=
1−cost |
将t=
π |
2 |
R=
π |
2 |
R=
看了 曲线x=t−sinty=1−...的网友还看了以下:
生铁和钢都是铁合金,生铁中碳的含量在2.O%~4.3%之间,钢中碳的含量在O.03%~2.O%之间 2020-05-14 …
已知圆O:x2+y2=4,动点P(t,0)(-2≤t≤2),曲线C:y=3|x-t|.曲线C与圆O 2020-05-15 …
在括号里填上恰当的词语,使句子意思更具体。1.()太阳()升起来了。2.()歌曲《让我们荡起双桨》 2020-06-23 …
已知曲线C1的参数方程为x=2cosθy=sinθ,曲线C2的极坐标方程为ρcos(θ−π4)=2 2020-07-13 …
线段OA=2(O为坐标原点),点A在x轴的正半轴上.现将线段OA绕点O逆时针旋转α度,且0<α<9 2020-07-25 …
已知曲线L:x=f(t)y=cost(0≤t<π2),其中函数f(t)具有连续导数,且f(0)=0 2020-07-31 …
已知圆O:x2+y2=4,将圆O上每一点的横坐标保持不变,纵坐标变为原来的12,得到曲线C.(I) 2020-08-01 …
(2014•南阳二模)如图所示气缸由两个截面不同的圆筒连接而成,活塞A、B被轻质刚性细杆连接在一起, 2020-11-02 …
(2006•宁德)学校要在校园一角建一处生物实验园地,园地入口处开一扇美观的非四边形小门.要求门宽最 2020-11-21 …
已知曲线C1的参数方程为x=2cosθy=sinθ,曲线C2的极坐标方程为ρcos(θ-π4)=2. 2021-02-10 …