Q. u=(6,−8)Find the direction angle of u. Enter your answer as an angle in degrees between 0∘ and 360∘ rounded to the nearest hundredth.θ=□∘
Calculate Tangent Ratio: To find the direction angle of the vectoru=(6,−8), we need to calculate the angle that this vector makes with the positive x-axis. The direction angle, often denoted as θ, can be found using the arctangent function (tan−1) which gives us the angle whose tangent is the ratio of the y-coordinate to the x-coordinate of the vector.
Use Arctangent Function: First, we calculate the tangent of the angle θ using the coordinates of u. The tangent of θ is the ratio of the y-coordinate to the x-coordinate.tan(θ)=xy=6−8=3−4.
Determine Quadrant: Next, we use the arctangent function to find the angle θ whose tangent is −34. We must be careful to place the angle in the correct quadrant. Since the x-coordinate is positive and the y-coordinate is negative, u is in the fourth quadrant where the direction angles are between 270∘ and 360∘.θ=arctan(−34).
Adjust for Quadrant: Using a calculator, we find the arctangent of −34. However, this will give us an angle in the second quadrant, so we must add 360∘ to get the angle in the fourth quadrant.θ=arctan(−34)+360∘.
Final Calculation: After calculating, we get: θ≈arctan(−34)+360∘≈−53.13∘+360∘≈306.87∘. We round this to the nearest hundredth as requested.
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