A generator at a regional Power Station produces an alternating voltage, according to the function, 𝑉 below:
? = 240sin(2?)
An electrical engineer needs to determine when this generator will have a voltage that is exactly +120 V.
i) How many times in the interval 0 ? ? ? 2? will the voltage reach +120 V?
ii) Determine the exact times when this occurs for 0 ? ? ? 2?.
I would like the answer to ii) with workings so I can see how it is done, I do not need i) answered.
Thanks
Answer
 The questioner was satisfied and accepted the answer, or
 The answer was disputed, but the judge evaluated it as 100% correct.
1 Attachment

Leave a comment if you need any clarifications.

Hi Philip, I believe that two of the solutions above produce a negative 120v, where we need the 4 times the voltage is a positive 120. Could you clarify further for me? Thanks!

I managed to see from your solution that positive 120 was just occuring pi/12 seconds on the other side of the x intercept to negative 120v. Wouldn't have got there without your help though, thank you!

Hi Kyshogle, I had unconsciously solved the equation 240cos(2t)=120. Sorry about that. Attached is the solution for 240sin (2t)=120. I apologize for any inconvenience this may have caused.
 answered
 80 views
 $4.00
Related Questions
 Double Inclined planes involving two weights connected
 Domain question
 Simplify this expression
 Is it true almost all Lebesgue measurable functions are nonintegrable?
 Compute $\lim_{x \rightarrow 0} \frac{1\arctan (\sin(x)+1)}{e^{x}1}$
 Find the derivative of the function $f(x)=\sqrt{\sin^2x+e^x+1}$
 Make a 2D polygon  but all the side lengths (bar one) are whole numbers, and all angles are multiples of 22.5
 A trigonometry question