What he did was correct all the way up until he it 9. He forgot to add the negative sign in front of the 9. You are adding -4 and -5 together. You will get -9.

7 0

4 years ago

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Dahasolnce [82]

Answer:

90° counter clockwise rotation of point 0(x, y) about origin = (-y, x)

Step-by-step explanation:

Following are the rules for a counter clockwise rotation of 90 degrees about the origin for a point O(x,y):

1. Invert the sign of the value of y.

2. Switch x and y with each other.

For example, a point A(5,2) after rotation gives a point B(-2,5) using the rules given above. The points on the x-y plane are shown in the image attached.

6 0

3 years ago