Question #61a0b

1 Answer
Jan 12, 2018

#tan((23pi)/3)=-tan(pi/3)=-sqrt3#

Explanation:

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consider the diagram of the quadrants above.

#tan((23pi)/3)#

each revolution of the quadrants is #2pi#

so we subtract multiples of #2pi# until we have a value

#0 <=theta <=2pi#

#((23pi)/3)-(6pi)/3=(17pi)/3>2pi#

#(17pi)/3-(6pi)/3=(11pi)/3>2pi#

#(11pi)/3-(6pi)/3=(5pi)/3<2pi#

we now decide which quadrant #(5pi)/3#is in

from the diagram

#(5pi)/3>(3pi)/2#

so it is in quadrant IV. where tan is negative

we required the angle with the #+x-#axis

#:.tan((23pi)/3)=-tan(2pi-((5pi)/3))#

#=-tan(pi/3)=-sqrt3.#