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3.4 Find the general solution in each of the following

{:[3.4.1,3sin theta=2cos theta],[3.4.2,2sin^(2)y-3cos y=4]:}

33.44 Find the general solution in each of the following\newline\begin{align*}\(\newline&3.4.1, &3\sin \theta=2\cos \theta,(\newline\)&3.4.2, &2\sin^{2}y-3\cos y=4\newline\end{align*}\)

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Q. 33.44 Find the general solution in each of the following\newline\begin{align*}\(\newline&3.4.1, &3\sin \theta=2\cos \theta,(\newline\)&3.4.2, &2\sin^{2}y-3\cos y=4\newline\end{align*}\)
  1. Identify Relationship: Identify the relationship between sin\sin and cos\cos in the first equation.\newlineUsing the identity sin(θ)=cos(90°θ)\sin(\theta) = \cos(90° - \theta), rewrite the equation:\newline3sin(θ)=2cos(θ)3\sin(\theta) = 2\cos(\theta)\newline3sin(θ)=2sin(90°θ)\Rightarrow 3\sin(\theta) = 2\sin(90° - \theta)
  2. Solve for Theta: Solve for θ\theta by dividing both sides by sin(θ)\sin(\theta), assuming sin(θ)0\sin(\theta) \neq 0.\newlinetan(θ)=23\tan(\theta) = \frac{2}{3}\newlineθ=arctan(23)+kπ\theta = \arctan\left(\frac{2}{3}\right) + k\pi, where kk is any integer
  3. Address Second Equation: Address the second equation, 2sin2(y)3cos(y)=42\sin^2(y) - 3\cos(y) = 4. Rewrite the equation in terms of sin2(y)\sin^2(y) and cos(y)\cos(y): 2sin2(y)3cos(y)=42\sin^2(y) - 3\cos(y) = 4
  4. Use Pythagorean Identity: Use the Pythagorean identity sin2(y)+cos2(y)=1\sin^2(y) + \cos^2(y) = 1 to substitute for sin2(y)\sin^2(y).\newlinesin2(y)=1cos2(y)\sin^2(y) = 1 - \cos^2(y)\newlinePlug this into the equation:\newline2(1cos2(y))3cos(y)=42(1 - \cos^2(y)) - 3\cos(y) = 4\newline22cos2(y)3cos(y)=4\Rightarrow 2 - 2\cos^2(y) - 3\cos(y) = 4\newline2cos2(y)+3cos(y)2=0\Rightarrow 2\cos^2(y) + 3\cos(y) - 2 = 0
  5. Solve Quadratic Equation: Solve the quadratic equation for cos(y)\cos(y). Using the quadratic formula, cos(y)=b±b24ac2a\cos(y) = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} a=2a = 2, b=3b = 3, c=2c = -2 cos(y)=3±3242(2)22\cos(y) = \frac{-3 \pm \sqrt{3^2 - 4\cdot2\cdot(-2)}}{2\cdot2} cos(y)=3±9+164\cos(y) = \frac{-3 \pm \sqrt{9 + 16}}{4} cos(y)=3±54\cos(y) = \frac{-3 \pm 5}{4} cos(y)=12\cos(y) = \frac{1}{2} or cos(y)=2\cos(y) = -2

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