The meaning of Sine of an angle

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[siddarthvenkateshgarikapati]

this is really cool sir no one tells us this in our entire trigo studies

[siddarthvenkateshgarikapati]

i didnt understand one thing what do you mean by saying that we are dealing with half angles so we are measuring half length please explain??

[GanitGenie]

Hi (Raj Verma), I really appreciate the effort taken to comment on this. Thank You. But, this is just for your information.
1. There are two approaches to trigonometry: 1. Unit Circle Approach to Trigonometry and 2. Right-angle approach to Trigonometry. In IndiaThe Unit-Circle approach to Trigonometry dates back to 5th century CE especially due to Aryabhata and still earlier in Egyptian and Babilonian mathematics.

2. In the video (at 04:24) I have clearly mentioned using a Caption that as we are working with half angles, we are measuring half length of the chord. You can take reference from any other resource which talks about the Why of Trigonometry. Especially when you refer to Unit Circle Approach, we will get the meaning of why we are considering half length of the chord.

3. The sinusoidal function is an application of Unit Circle Approach to Trigonometry which is highly missing in our curriculum.
There are many resources explaining the applications of Unit Circle Approach. I would really appreciate, if you could refer to those as well. Thank You.

[deepakbellur]

Raj Verma (in his comment) says "the name of the function is sin or sine because of the sinusoidal curve".
My question is whether the word 'Sinusoidal' meaning 'like a sine' came because of the Sine curve or whether the word Sine came because of the word sinusoidal?
Like others I too did not understand what you mean by 'half angles'. What would a full angle be?

[jenpedia]

Hi very informative lecture...which softwere or devicw do u use to record these lectures?

[Rajverma-jkil]

The explanation is entirely wrong.
A chord is a line segment obtained when you join any two points on circle. You can't measure the length of the perpendicular on or above x-axis and state it as the length of chord.
One more addition, the name of the function is sin or sine because of the sinusoidal curve (that curve you have drawn up and down).
One good point:
1. General knowledge ( Jivah or chord)

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