SOLUTION: Solve the following equations give that 0 &#8804; x < 2&#960; a) {{{ cos^2 (x) -sin^2 (x) = -1 }}} b) {{{ 1 + sqrt (3) tan (2x) = 0 }}} --Need a refresher on how to so

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Question 1094407: Solve the following equations give that 0 ≤ x < 2π
a)

b)

--Need a refresher on how to solve these, I would appreciate any sort of help!

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Solve the following equations give that 0 ≤ x < 2π
a)
Sub (1 - sin^2) for cos^2
------
--> 1 - 2sin^2 = -1
sin^2 = 1
sin = 1, x = pi/2
sin = -1, x = 3pi/2
==================
Or use cos^2(x) - sin^2(x) = cos(2x)
cos(2x) = -1
2x = pi, 3pi
x = pi/2, 3pi/2
===========================================
b)
tan(2x) = -sqrt(3)/3
2x = 150 degs, 330 degs, 510 degs, 690 deg
x = 75, 165, 255, 345 degs
Convert to radians.


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