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How do you evaluate #Arctan (-1)#?

Answer 1

#-45#

Press 1 on calculator then change sign key #-1# displayed on screen, now press arctan #=-45# On hp9s calculater press "2ndf " then "tan"

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Answer 2

Zoe Austin

To evaluate arctan(-1), you're finding the angle whose tangent is -1. Since tangent is negative in the second and fourth quadrants, and arctan gives values in the range of -π/2 to π/2, the angle you're looking for is in the fourth quadrant. Thus, arctan(-1) = -π/4.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.