Question #3aca5
1 Answer
Jun 16, 2017
Explanation:
1/(sec^2 x) + 3sin (x/2)cos (x/2) = 0
since
Solve this quadratic equation for sin x.
There are 2 real roots:
Trig table and unit circle give:
Check by calculator.
x/2 = 105 --> cos (x/2) = -0.258 --> sin (x/2) = 0.966.
cos^2 x + 3sin (x/2).cos (x/2) = 0.75 + 3(-0.258)(0.966) =
= 0.75 - 0.75 = 0. Correct.