A teacher states that the small-angle approximation is appropriate if sinθ differs from θ by less than 5%. A student pulls a pendulum to an initial angle of 20∘ before release.
Which of the following is most nearly correct about using the small-angle approximation for this release angle?
a) The difference between sinθ and θ is about 0.7%, so the approximation is acceptable.
b) The difference between sinθ and θ is about 6%, so the approximation is not acceptable.
c) The difference between sinθ and θ is about 2%, so the approximation is acceptable.
d) The difference between sinθ and θ is about 4%, so the approximation is acceptable.