Find an Online Tutor Now

Jonathan Z.

asked • 05/16/20

How do you solve for t in 50 = 90sin(2pi*t / 26 + 3pi / 2) +115

50 = 90sin(2pi*t / 26 + 3pi / 2) +115

I am not allowed to solve this by drawing a graph. Hence, I have to show working.

I understand that I have to carry over the 115 and divide both sides by 90 which will get me

sin(2pi*t/26 + 3pi/2) = -13/18

For the next step, I think I am wrong as I did this

2pi*t/26 + 3pi/2 = 0.807

26(0.807 - 3pi/2) / 2pi


-16.16 + pi = -13

2pi - (-16.16) = 22.44

This is clearly wrong as the answers are 3.16 and 22.8 according to desmos. Is there a concept I am unaware of? Regardless, it would be best if you could show me the correct working anyway.

1 Expert Answer


Jonathan Z.

Thanks a lot, you saved my skin!


Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.


Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.