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Question
Using the formula, sin A = `sqrt((1-cos 2A)/2) ` find the value of sin 300, it being given that cos 600 = `1/2`
Solution
A = 300
⇒ 2A = 2 × 300 = 600
By substituting the value of the given T-ratio, we get:
sin A =`sqrt((1- cos 2A)/2)`
sin `30^0 = sqrt((1-cos 60^0)/2) = sqrt(1-1/2)/2 = sqrt((1/2)/2) = sqrt(1/4) =1/2`
∴ sin `30^0 = 1/2`
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