Learn how to solve trigonometric equations problems step by step online. Solve the trigonometric equation 3sin(x)+1=-cos(2x). Move everything to the left hand side of the equation. Applying an identity of double-angle cosine: \cos\left(2\theta\right)=1-2\sin\left(\theta\right)^2. We can try to factor the expression 3\sin\left(x\right)+2-2\sin\left(x\right)^2 by applying the following substitution. Substituting in the polynomial, the expression results in.

Solve the trigonometric equation 3sin(x)+1=-cos(2x)