Question
Download Solution PDFIn a triangle ABC, a = 4, b = 3, c = 2. What is cos 3C equal to ?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept:
For a triangle ABC, with sides a, b, c opposite to angle A, B, C respectively.
Cosine formula-
- cos 3x = 4cos3x - 3cos x
Calculation:
Given: a triangle ABC with a = 4, b = 3, c = 2.
⇒
⇒
⇒ cos C =
So cos 3C = 4cos3C - 3cos C
⇒
⇒
⇒
⇒
∴ The correct option is (1).
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