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Doctors Medicines MCQs Q&A

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2cos 2x.tan x + cos 2x = 0
cos 2x(2tan x + 1) = 0
Trig unit circle and trig table -->
a. cos 2x = 0 --> $2x = pi/2$ and $2x = (3pi)/2$
$2x = pi/2 --> x = pi/4$
$2x = (3pi)/2 --> x = (3pi)/4$
b. 2tan x + 1 = 0
$tan x = - 1/2$
Calculator and trig unit circle -->
$tan x = - 1/2$ --> $x = - 26^@57$ and $x = 180 - 26.57 = 153^@43$
Answers for (0, 2pi):
$pi/4; (3pi)/4 , 153^@43, and 333^@43$ (or -26.57)

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