If the \( \triangle \mathrm{ABC} \) is acute angled at \( \mathrm{C} \) then
(a) \( \cos 2 A+\co...
If the \( \triangle \mathrm{ABC} \) is acute angled at \( \mathrm{C} \) then
(a) \( \cos 2 A+\cos 2 B-\cos 2 C1 \)
(b) \( \cos 2 A+\cos 2 B+\cos 2 C1 \)
(c) \( \cos ^{2} A+\cos ^{2} B+\cos ^{2} C1 \)
(d) none of these
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