3.4 Find the general solution in each of the following\begin{align*}\(\newline&3.4.1, &3\sin \theta=2\cos \theta,(\newline\)&3.4.2, &2\sin^{2}y-3\cos y=4\end{align*}\)
Q. 3.4 Find the general solution in each of the following\begin{align*}\(\newline&3.4.1, &3\sin \theta=2\cos \theta,(\newline\)&3.4.2, &2\sin^{2}y-3\cos y=4\end{align*}\)
Identify Relationship: Identify the relationship between sin and cos in the first equation.Using the identity sin(θ)=cos(90°−θ), rewrite the equation:3sin(θ)=2cos(θ)⇒3sin(θ)=2sin(90°−θ)
Solve for Theta: Solve for θ by dividing both sides by sin(θ), assuming sin(θ)=0.tan(θ)=32θ=arctan(32)+kπ, where k is any integer
Address Second Equation: Address the second equation, 2sin2(y)−3cos(y)=4. Rewrite the equation in terms of sin2(y) and cos(y): 2sin2(y)−3cos(y)=4
Use Pythagorean Identity: Use the Pythagorean identity sin2(y)+cos2(y)=1 to substitute for sin2(y).sin2(y)=1−cos2(y)Plug this into the equation:2(1−cos2(y))−3cos(y)=4⇒2−2cos2(y)−3cos(y)=4⇒2cos2(y)+3cos(y)−2=0
Solve Quadratic Equation: Solve the quadratic equation for cos(y). Using the quadratic formula, cos(y)=2a−b±b2−4aca=2, b=3, c=−2cos(y)=2⋅2−3±32−4⋅2⋅(−2)cos(y)=4−3±9+16cos(y)=4−3±5cos(y)=21 or cos(y)=−2
More problems from Sine and cosine of complementary angles