How do tan, sin and cos work? - Quora

What is the meaning of sine, cosine and other trigonometric identities? - Quora

How do tan, sin and cos work? - Quora

What actually are sine, cosine and tangent? - Quora

If tan θ is positive and sin θ is negative, in which quadrant does θ lie? - Quora

How do tan, sin and cos work? - Quora

How to find the values of the six trigonometric functions given the point (-3/5. 4/5) which lies on the terminating side - Quora

Why and how exactly do sine, cosine and tangent work? What are they? - Quora

What is the definition of cosine, sine, etc.? - Quora

Why is the period of tanx pi, but the periods of cos and sin are both 2pi? - Quora