How cool is trig
Sine and cosine of an angle defined using the unit circle. Think about that. You can determine every point along that Unit Circle knowing the radius and using Sin and cosine of that angle.
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JoyfulSilence · 51-55, M
Also, draw a line tangent to the circle, touching it at the point P where the radius at angle theta touches the circle.
Suppose the tangent line intersects the x-axis at the point A=(a,0), and intersects the y-axis at the point B = (0,b).
Then the length of the segment AP on the tangent line equals the tangent of theta.
The length of the segment BP equals the cotangent of theta which is the tangent of the complemantary angle of theta
a = secant of theta
b = cosecant of theta = secant of the complemantary angle of theta
The cosine is the sine of the complemantary angle of theta
Suppose the tangent line intersects the x-axis at the point A=(a,0), and intersects the y-axis at the point B = (0,b).
Then the length of the segment AP on the tangent line equals the tangent of theta.
The length of the segment BP equals the cotangent of theta which is the tangent of the complemantary angle of theta
a = secant of theta
b = cosecant of theta = secant of the complemantary angle of theta
The cosine is the sine of the complemantary angle of theta