Q. Find all angles, 0∘≤θ<360∘, that satisfy the equation below, to the nearest tenth of a degree.cot2θ−5cotθ+6=0Answer: θ=
Identify Trigonometric Equation: Let's first identify the trigonometric equation we need to solve:cot2(θ)−5cot(θ)+6=0This is a quadratic equation in terms of cot(θ). To solve it, we can factor the left-hand side of the equation.
Factor Quadratic Equation: We look for two numbers that multiply to 6 and add up to −5. These numbers are −2 and −3. So we can factor the equation as follows:(cot(θ)−2)(cot(θ)−3)=0
Solve First Equation: Now we have two separate equations to solve:1. cot(θ)−2=02. cot(θ)−3=0
Find Angle with Cotangent 2: Solving the first equation, cot(θ)−2=0, we get:cot(θ)=2Now we need to find the angles θ that have a cotangent of 2.
Find Angle in Third Quadrant: The cotangent of an angle is the reciprocal of the tangent. So we are looking for angles where tan(θ)=21. We can use the arctangent function to find the principal value of θ: θ=arctan(21)
Solve Second Equation: Using a calculator, we find the principal value: θ≈arctan(21)≈26.6 degrees However, since the cotangent function is positive in the first and third quadrants, we need to find the other angle in the third quadrant that also has the same cotangent value.
Find Angle with Cotangent 3: To find the angle in the third quadrant, we add 180 degrees to the principal value:θ≈26.6 degrees +180 degrees ≈206.6 degreesNow we have two angles that satisfy the first equation: 26.6 degrees and 206.6 degrees.
Combine Solutions: Next, we solve the second equation, cot(θ)−3=0, which gives us:cot(θ)=3 We repeat the process to find the angles where tan(θ)=31.
Combine Solutions: Next, we solve the second equation, cot(θ)−3=0, which gives us:cot(θ)=3We repeat the process to find the angles where tan(θ)=31.Using the arctangent function again, we find the principal value:θ=arctan(31)
Combine Solutions: Next, we solve the second equation, cot(θ)−3=0, which gives us:cot(θ)=3We repeat the process to find the angles where tan(θ)=31.Using the arctangent function again, we find the principal value:θ=arctan(31)Using a calculator, we find the principal value:θ≈arctan(31)≈18.4 degreesAgain, we need to find the angle in the third quadrant with the same cotangent value.
Combine Solutions: Next, we solve the second equation, cot(θ)−3=0, which gives us:cot(θ)=3We repeat the process to find the angles where tan(θ)=31.Using the arctangent function again, we find the principal value:θ=arctan(31)Using a calculator, we find the principal value:θ≈arctan(31)≈18.4 degreesAgain, we need to find the angle in the third quadrant with the same cotangent value.To find the angle in the third quadrant, we add 180 degrees to the principal value:θ≈18.4 degrees +180 degrees ≈198.4 degreesNow we have two more angles that satisfy the second equation: 18.4 degrees and cot(θ)=30 degrees.
Combine Solutions: Next, we solve the second equation, cot(θ)−3=0, which gives us:cot(θ)=3We repeat the process to find the angles where tan(θ)=31.Using the arctangent function again, we find the principal value:θ=arctan(31)Using a calculator, we find the principal value:θ≈arctan(31)≈18.4 degreesAgain, we need to find the angle in the third quadrant with the same cotangent value.To find the angle in the third quadrant, we add 180 degrees to the principal value:θ≈18.4 degrees +180 degrees ≈198.4 degreesNow we have two more angles that satisfy the second equation: 18.4 degrees and cot(θ)=30 degrees.Combining the solutions from both equations, we have four angles that satisfy the original equation:cot(θ)=31 degrees, cot(θ)=32 degrees, 18.4 degrees, and cot(θ)=30 degrees.These are the angles between cot(θ)=35 and cot(θ)=36 degrees that satisfy the given trigonometric equation to the nearest tenth of a degree.
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