Coordinates of sin(2x)=1/2

[markosheehan]

can some one help me with part b finding the co-ordinates of p. i tried this by letting sin 2x=1/2 but when i work out x i do not get the right answer. the right answer is (17pi/12, 1/2)​

 

[Deleted member 4993]

can some one help me with part b finding the co-ordinates of p. i tried this by letting sin 2x=1/2 but when i work out x i do not get the right answer. the right answer is (17pi/12, 1/2)​

sin^-1(2x) is multi-valued. You'll need to define the domain for your answer first. Then:

sin(2x) = 1/2 → 2x = π/6, (π - π/6), (2π + π/6) ......

So choose the appropriate value for the given domain.

 

[markosheehan]

I don't get how x can be pi/12 and 5pi/12 can you explain this to me

 

[stapel]

I don't get how x can be pi/12 and 5pi/12 can you explain this to me

When you study trig, you'll be taught about "sinusoidal waves" such as the sine curve, where the curve takes on the same values over and over again, repeating itself each "period" for the sine function. This is why there will be (infinitely-)many x-values for the solution.

We can't teach courses here, so we can't "explain" the chapters of material necessary to get you to the necessary point. Sorry.