z=−2−5iFind the angle θ (in radians) that z makes in the complex plane. Round your answer, if necessary, to the nearest thousandth. Express θ between −π and π.θ=
Q. z=−2−5iFind the angle θ (in radians) that z makes in the complex plane. Round your answer, if necessary, to the nearest thousandth. Express θ between −π and π.θ=
Calculate Argument of z: To find the angle θ, we need to calculate the argument of the complex number z=−2−5i. The argument is the angle the complex number makes with the positive x-axis in the complex plane.
Determine Quadrant for Angle: The argument of a complex number a+bi is given by arctan(ab), but since our a is negative and b is negative, the angle will be in the third quadrant. We need to add π to the arctan value to get the correct angle in the range of −π to π.
Calculate Arctan Value: First, calculate the arctan value: arctan(25). This is the angle in the first quadrant, but we need the angle in the third quadrant.
Adjust Angle for Third Quadrant: Using a calculator, we find arctan(25)≈1.190.
Add Pi to Arctan Value: Since the angle is in the third quadrant, we add π to get the angle in the correct range: 1.190+π.
Calculate Final Angle: Adding 1.190 to π gives us approximately 1.190+3.142=4.332.
Ensure Angle Range: However, we need to ensure the angle is between −π and π. Since 4.332 is greater than π, we subtract 2π to get the angle in the correct range.
Final Angle Calculation: Subtracting 2π from 4.332 gives us 4.332−2×3.142=−1.952.
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