Question

when a point $(a,b)$ is rotated counterclockwise about the origin, $(a,b)\to(b, -a)$ is the result of a rotation of

Explanation:

Step1: Recall rotation rules

For a point \((x,y)\) rotated counter - clockwise about the origin:

• \(90^{\circ}\): \((x,y)\to(-y,x)\)
• \(180^{\circ}\): \((x,y)\to(-x,-y)\)
• \(270^{\circ}\): \((x,y)\to(y, - x)\)

Answer:

\(270^{\circ}\)