MathLabs

Problem 4

Find all real solutions of cos⁡2x+cos⁡22x+cos⁡23x=1\cos^2 x+\cos^2 2x+\cos^2 3x=1.
Step 2 of 5: Substitute into the equation
c2+(2c2−1)2+(4c3−3c)2=1c^2+(2c^2-1)^2+(4c^3-3c)^2=1
Detailed analysis

Substitution changes the original equation into the polynomial equation c2+(2c2−1)2+(4c3−3c)2=1c^2+(2c^2-1)^2+(4c^3-3c)^2=1.