DimaMazin Posted March 11, 2021 Posted March 11, 2021 (61/2 - 21/2)/4 = (2 - 31/2)1/2/2 I have taken sin * cos=1/4 then I have got sine=(2 - 31/2)1/2/2 or (2 + 31/2)1/2/2 Calculator has shown arcsin=15 degrees but sine 15 degrees=(61/2 - 21/2)/4 I don't understand how they are connected.
Ghideon Posted March 11, 2021 Posted March 11, 2021 1 hour ago, DimaMazin said: (61/2 - 21/2)/4 = (2 - 31/2)1/2/2 Hope this helps: yes the equality holds; quick check using Wolfram alpha gives that is equal to reference: https://www.wolframalpha.com/input/?i=(6^0.5-2^0.5)%2F4 1 hour ago, DimaMazin said: sin * cos=1/4 Not sure what that means
DimaMazin Posted March 12, 2021 Author Posted March 12, 2021 21 hours ago, Ghideon said: Hope this helps: yes the equality holds; quick check using Wolfram alpha gives that is equal to reference: https://www.wolframalpha.com/input/?i=(6^0.5-2^0.5)%2F4 Not sure what that means For example one circular sector of unit circle has area a/2, other circular sector has area Pi/4 - a/2 then a/2=sin(a)*cosin(a)/2 +(area of circular segment of angle 2a)/2 and Pi/4 - a/2 = sin(a)*cosin(a)/2+(area of circular segment of angle Pi - 2a)/2 Then area of the twq equal triangles is sin*cosin
Bufofrog Posted March 12, 2021 Posted March 12, 2021 46 minutes ago, DimaMazin said: For example one circular sector of unit circle has area a/2, So the area in question is 1/2 of the circle? 48 minutes ago, DimaMazin said: other circular sector has area Pi/4 - a/2 So that would mean that Pi/4 is the total area 'a'. Since Pi r^2 = area of a circle, Pi r^2 = Pi/4 or r = 0.5. Is that correct? Or are these areas small circles in the larger circle?
DimaMazin Posted March 12, 2021 Author Posted March 12, 2021 7 hours ago, Bufofrog said: So the area in question is 1/2 of the circle? So that would mean that Pi/4 is the total area 'a'. Since Pi r^2 = area of a circle, Pi r^2 = Pi/4 or r = 0.5. Is that correct? Or are these areas small circles in the larger circle? Unit circle has r=1. a is angle in radians. You have confused in your inattentiveness . (61/2 - 21/2)/4 = (2-31/2)1/2/2 21/2(31/2-1)/2=(2-31/2)1/2 (31/2-1)2/2=2-31/2 3-2*31/2+1=4-2*31/2
Bufofrog Posted March 13, 2021 Posted March 13, 2021 10 hours ago, DimaMazin said: For example one circular sector of unit circle has area a/2, other circular sector has area Pi/4 - a/2 What do you mean by a sector? The area of a quadrant of the unit circle is Pi/4 and the area of the unit circle is Pi. What are these 2 sectors and why the relationship between the 2?
DimaMazin Posted March 13, 2021 Author Posted March 13, 2021 3 hours ago, Bufofrog said: What do you mean by a sector? The area of a quadrant of the unit circle is Pi/4 and the area of the unit circle is Pi. What are these 2 sectors and why the relationship between the 2? https://en.wikipedia.org/wiki/Circular_sector When sin*cosin=1/4 then area of the one sector is Pi/24 and area of second sector is 5Pi/24
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