Sum and difference identities
Find the coordinates of P(Ï€/12)
x = (1+√3)/(2√2)
To find the y-coordinate you use the identity:
sin(α- β) = (sinα)(cosβ) (cosα)(sinβ)
Why do we use this identity? eg, why don't we use
sin(α + β) = (sinα)(cosβ) + (cosα)(sinβ) ??
https://brainmass.com/math/complex-analysis/sum-difference-identities-28527
Solution Preview
To find y_coordinate, we can use
y=sqrt(1-x^2)=(-1+√3)/(2√2)
If we use identities, then we let β=Ï€/12 and α=Ï€/6, then ...
Solution Summary
This solution shows how to use the difference identity to find coordinates.
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