SOLUTION: Evaluate tan(-240 degrees( The correct answer is one of the following. Which one? A) 1/2 B) (square root of 2)/2 C) - (square root of 3) D)

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Question 1198657: Evaluate tan(-240 degrees(
The correct answer is one of the following. Which one?
A) 1/2
B) (square root of 2)/2
C) - (square root of 3)
D) - (square root of2)/2
E) (square root of 3)/2
Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
tan(-240) = - 1.732050808, according to my calculator.

without a calculator, i would probably do the following:

add 360 to -240 to get 120 degrees.
the equivalent angle in the first quadrant is 180 minus 120 = 60 degrees.
tan(60) = (sqrt(3)/2)/(1/2) = sqrt(3).
tangent in the second quadrant is negative, so tan(120) = -sqrt(3).
using my calculator, i find that -sqrt(3) = - 1.732050808.
this is the same i got using my calculator directly on -240 degrees.

solution is therefore -sqrt(3) which is equal to selection C.

if you graph tan(-240), you will find the same answer, as shown below:

SOLUTION: Evaluate tan(-240 degrees( The correct answer is one of the following. Which one? A) 1/2 B) (square root of 2)/2 C) - (square root of 3) D) - (square root of2)/2