How do you solve sqrt3+tan(2x)=0 between the interval 0<=x<=2pi?

1 Answer
Mar 21, 2018

pi/3; (5pi)/6

Explanation:

tan 2x = -sqrt3
Trig table and unit circle gve 2 solutions:
2x = (2pi/3), and 2x = (2pi/3) + pi = (5pi)/3
a. 2x = (2pi)/3
x = pi/3
b. 2x = (5pi)/3
x = (5pi)/6
Check.
x = pi/3 --> tan 2x = tan ((2pi)/3) = -sqrt3.
sqrt3 + tan 2x = sqrt3 - sqrt3 = 0. Proved
x = (5pi)/6 --> tan (10pi)/6 = tan (5pi)/3 = tan (2pi)/3 = - sqrt3
sqrt3 + tan 2x = sqrt3 - sqrt3 = 0. Proved.