Although the algebra of rotations can get ugly, the main idea is that rotation through an appropriate angle will transform a general second-degree equation into an equation in 𝑥′ and 𝑦′ without an 𝑥′𝑦′−term.Group of answer choicesTrueFalse

What happens to the equation 𝑥2+𝑦2=𝑟2 in a rotated 𝑥′𝑦′−system?Group of answer choicesIn a rotated 𝑥′𝑦′-system, 𝑥′ replaces 𝑥 and 𝑦′ replaces 𝑦.In a rotated 𝑥′𝑦′-system, 1 replaces 𝑥 and 1 replaces 𝑦.In a rotated 𝑥′𝑦′-system, 1 replaces and 𝑦′ replaces 𝑦.In a rotated 𝑥′𝑦′-system, 𝑥′ replaces 𝑥 and 1 replaces 𝑦.

It is easier to write sin⁡2𝜃=2sin⁡𝜃 and not bother with memorizing the double-angle formula.Group of answer choicesTrueFalse

What special name can be given to a quadrilateral PQRS if the ∠P + ∠S =180°?

Fill-in-the-blank: A _____________ of fundamental rotations about the unit vectors cause composite rotations.

Two angles whose sum is equal to 180° are called