Answer:
1. (x,y)→(y,-x)
2. (x,y)→(-y,x)
3. (x,y)→(-x,-y)
Step-by-step explanation:
1. Rotation 90° clockwise (or 270° counterclockwise) about the origin changes x into y and y into -x, so it has the rule
(x,y)→(y,-x)
2. Rotation 90° counterclockwise (or 270° clockwise) about the origin changes x into -y and y into x, so it has the rule
(x,y)→(-y,x)
3. Rotation 180° clockwise about the origin changes x into y and y into -x, so it has the rule
(x,y)→(-x,-y)
Here you can apply rotation by 90° clockwise twice, so
(x,y)→(-y,x)→(-x,-y)
Answer:
The answer is 3
Step-by-step explanation:
4 x 3 = 12
8 + 12 = 20
5p-9=2p+12
+9 +9
5p= 2p+21
-2p -2p
3p/3=21/3
p=7
Given :
A function , x = 2cos t -3sin t .....equation 1.
A differential equation , x'' + x = 0 .....equation 2.
To Find :
Whether the given function is a solution to the given differential equation.
Solution :
First derivative of x :

Now , second derivative :

( Note : derivative of sin t is cos t and cos t is -sin t )
Putting value of x'' and x in equation 2 , we get :
=(-2cos t + 3sin t ) + ( 2cos t -3sin t )
= 0
So , x'' and x satisfy equation 2.
Therefore , x function is a solution of given differential equation .
Hence , this is the required solution .