Trigonometry Question

[harryyeah]

Find a value for x knowing that:

2sinx+1=0

cos-1(sqrt(3)/2) = x

and,

0<x<2pi


I'm not sure how to do this question - any help would be much appreciated!

 

[Deleted member 4993]

Find a value for x knowing that:

2sinx+1=0

cos-1(sqrt(3)/2) = x

and,

0<x<2pi


I'm not sure how to do this question - any help would be much appreciated!

Look at the unit circle and deduce:

at what angle/s Θ you get cos(Θ) = (√3)/2

and

at what angle/s Θ you get sin(Θ) = -1/2

 

[HallsofIvy]

Equivalently, take an equilateral triangle, each side of length 2 and draw a line from one vertex perpendicular to the opposite side. You now have two right triangles with hypotenuse of length 2 and one leg of length 1. What is the length of the other leg? What are the two acute angles in the right triangle?

 

[harryyeah]

Thanks for the help!