Tell whether the statement is true or false.
-cos (ϴ + 90°)
A)-cos ϴ
B)-sin ϴ
C)cos ϴ
D)sin ϴ

Name: Tell whether the statement is true or false. -cos (ϴ + 90°) A)-cos ϴ B)-sin ϴ C)cos ϴ D)sin ϴ
Brand: Quizplus
Rating: 4.9 (41 reviews)

Question

Quizplus · Accepted Answer

The statement is true for option B, $\cos(\theta + 90^\circ) = -\sin \theta$. This is because when you add 90 degrees to an angle in trigonometry, it effectively shifts the function from cosine to its co-function, sine, but in this case, it also inverts the sign, hence $-\sin \theta$.

Tell Whether the Statement Is True or False