The value of is equal to

Question

The value of  is equal to

Canvas Classes · Accepted Answer

🧠 Reduce the Trig Values First — Then Recognise

The expression inside  is . Before doing anything else, simplify the trig values of these specific angles using the period.

. Since cosine has period , .

.

So the fraction becomes . Clear the denominator: multiply numerator and denominator by  to get .

Now we need . The value  should ring a bell — it is . The standard fact: .

So .

🗺️ Working It Out

Reduce the cosine using periodicity: .

So the bracket is .

Now . Since , we have .

And

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