(1 + cos 9A)/(1 + cos A) = [16cos^4 A - 8cos^3 A - 12cos^2 A + 4cos A + 1] ^ 2
You asked:
Solve the equation \(\frac{1 + \cos\left( 9 A \right)}{1 + \cos\left( A \right)} = {\left( 16 \cdot {\cos\left( A \right)}^{4} - 8 \cdot {\cos\left( A \right)}^{3} - 12 \cdot {\cos\left( A \right)}^{2} + 4 \cdot \cos\left( A \right) + 1 \right)}^{2}\) for the variable \(A\).
MathBot Answer:
The complex solutions are: \[\mathbb{C}\]