10/13/22 - Sine and Cosine Functions Flashcards
1
Q
If θ is an angle and (x, y) is the reference point of θ on the unit circle, which coordinate is cos(θ)?
A
cos(θ) = the x-coordinate on the unit circle
2
Q
If θ is an angle and (x, y) is the reference point of θ on the unit circle, which coordinate is sin(θ)?
A
sin(θ) = the y-coordinate on the unit circle
3
Q
Are sin(θ) and cos(θ) functions? What is their input?
A
They are functions with input θ.
4
Q
What is the Pythagorean Identity?
A
For an angle θ, cos^2(θ) + sin^2(θ) = 1.
5
Q
What are similar triangles?
A
Triangles with the same interior angles, the ratio of their sides is constant.
6
Q
How is tan(θ) defined?
A
tan θ = (sin θ)/(cos θ)
