Question

16. Solve for the angle x.
cos(¹/2x) = ¹/2

Answer 1

We know that ,

`\rightarrow \tt \cos( (\pi)/(3) ) = (1)/(2)`

So ,

`\: \rightarrow \tt \cos( (1)/(2)x ) = \cos( (\pi)/(3) ) \\ \\ \rightarrow \tt (1)/(2).x = (\pi)/(3) \\ \\ \rightarrow \tt x = (2\pi)/(3)`

we can add 2 pi to it since there will be no change in the value

Also,

`\: \rightarrow \tt \cos( (14\pi)/(6) ) = (1)/(2) \\ \\ \\ \rightarrow \tt (1)/(2) x = (14\pi)/(6) \\ \\ \rightarrow \tt x = (7\pi)/(3)`

Answer : Option B