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Find all angles, 
0^(@) <= theta < 360^(@), that satisfy the equation below, to the nearest tenth of a degree.

4cos^(2)theta=4cos theta-1
Answer: 
theta=

Find all angles, 0^{\circ} \leq \theta<360^{\circ} , that satisfy the equation below, to the nearest tenth of a degree.\newline4cos2θ=4cosθ1 4 \cos ^{2} \theta=4 \cos \theta-1 \newlineAnswer: θ= \theta=

Full solution

Q. Find all angles, 0θ<360 0^{\circ} \leq \theta<360^{\circ} , that satisfy the equation below, to the nearest tenth of a degree.\newline4cos2θ=4cosθ1 4 \cos ^{2} \theta=4 \cos \theta-1 \newlineAnswer: θ= \theta=
  1. Rewrite Equation: Rewrite the given equation in standard quadratic form.\newlineThe given equation is 4cos2(θ)=4cos(θ)14\cos^2(\theta) = 4\cos(\theta) - 1. To solve for θ\theta, we need to rewrite this equation in the form of a quadratic equation ax2+bx+c=0ax^2 + bx + c = 0.\newlineSubtract 4cos(θ)4\cos(\theta) and add 11 to both sides to get:\newline4cos2(θ)4cos(θ)+1=04\cos^2(\theta) - 4\cos(\theta) + 1 = 0
  2. Factor Quadratic: Factor the quadratic equation.\newlineThe equation 4cos2(θ)4cos(θ)+1=04\cos^2(\theta) - 4\cos(\theta) + 1 = 0 is a quadratic equation in terms of cos(θ)\cos(\theta). We can factor this equation as:\newline(2cos(θ)1)2=0(2\cos(\theta) - 1)^2 = 0
  3. Solve for cos(θ)\cos(\theta): Solve for cos(θ)\cos(\theta). Since we have a perfect square, we can take the square root of both sides to get: 2cos(θ)1=02\cos(\theta) - 1 = 0 Now, add 11 to both sides: 2cos(θ)=12\cos(\theta) = 1 Divide both sides by 22: cos(θ)=12\cos(\theta) = \frac{1}{2}
  4. Find Corresponding Angles: Find the angles that correspond to cos(θ)=12\cos(\theta) = \frac{1}{2}. The cosine function is positive and equals 12\frac{1}{2} at specific angles within the range of 00^\circ to 360360^\circ. These angles are 6060^\circ and 300300^\circ, as cosine is positive in the first and fourth quadrants.
  5. Check Additional Solutions: Check for any additional solutions within the given range.\newlineSince the cosine function is periodic with a period of 360°360°, we need to check if there are any other angles within the range of 0° to 360°360° that satisfy the equation. However, since we have already identified the angles where cos(θ)=12\cos(\theta) = \frac{1}{2} within one period, there are no additional solutions.

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