Created on 2024-06-20Asked by Aria Williams (Solvelet student)
Solve the trigonometric equation cos(2x)+3sin(x)=0 for 0≤x≤2π.
Solution
To solve the trigonometric equation cos(2x)+3sin(x)=0: 1. \textbf{Express cos(2x) using a double-angle identity:} cos(2x)=1−2sin2(x) Substitute this into the original equation: 1−2sin2(x)+3sin(x)=0 2. \textbf{Let u=sin(x):} 1−2u2+3u=0 3. \textbf{Rearrange the equation into standard quadratic form:} −2u2+3u+1=0 Multiply through by −1 to simplify: 2u2−3u−1=0 4. \textbf{Solve the quadratic equation:} Using the quadratic formula u=2a−b±b2−4ac, where a=2, b=−3, and c=−1: u=2⋅23±(3)2−4⋅2⋅(−1)u=43±3+8u=43±11 5. \textbf{Find the possible values of u=sin(x):} u1=43+11u2=43−11 Since sin(x) must be between −1 and 1, check the values: 43−11<−1(not valid) Thus, the only valid solution is: sin(x)=43+11 6. \textbf{Solve for x:} x=sin−1(43+11) Since sin(x) must be in the range [0,2π], we have two solutions: x1=sin−1(43+11)x2=π−sin−1(43+11) 7. \textbf{Result:} The solutions to the equation cos(2x)+3sin(x)=0 for 0≤x≤2π are: x=sin−1(43+11)andx=π−sin−1(43+11)Solved on Solvelet with Basic AI Model
Some of the related questions asked by Daniel Martinez on Solvelet
DefinitionA trigonometric equation consists of a trigonometric function, such as sine, cosine, or tangent, and is solved for the particular angle or value. Example: Solve sin(x)=21. X=6π+2kπ and x=65π+2kπ