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Problem

Ryker tried to solve the following equation, where



is in radians to the nearest hundredth, in the interval from



to



, but he made a mistake.



Here is Ryker's work.













Of the solutions, only



is in the interval from



to



, so



.

What was Ryker's mistake?

Choose 1 answer:

Choose 1 answer:

(Choice A) Ryker evaluated



in degrees instead of in radians.

A

Ryker evaluated



in degrees instead of in radians.

(Choice B) Ryker used an identity that only applies to the sine function, not to the cosine function.

B

Ryker used an identity that only applies to the sine function, not to the cosine function.

(Choice C) Ryker forgot to use negative



-values which would reveal more solutions in the interval.

C

Ryker forgot to use negative



-values which would reveal more solutions in the interval.

(Choice D) Ryker gave solutions that were outside of the interval.

D

Ryker gave solutions that were outside of the interval.