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If \( cosA+cosB+cosC=0\), \( sinA+sinB+sinC=0\) and \( A+B+C={180}^{0}\), then the value of \( cos3A+cos3B+cos3C\) is

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Solution

Solution for If  cosA+cosB+cosC=0,  sinA+sinB+sinC=0 and  A+B+C={180}^{0}, then the value of  cos3A+cos3B+cos3C is
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