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Trig Problem

  • Thread starter kuahji
  • Start date
  • #1
394
2
The question is Solve the trig equation for all values of the variable in the first positive rotation.

Problem cos^2 3x = 1

Heres how I attempted to solve the equation

3x = arccos (1)^2

1/3 arccos 1

cos = 0 & 180

However, on the test, the professor stated there were 4 more solutions & I'm having trouble trying to figure them out. What more do I need to do?
 

Answers and Replies

  • #2
Päällikkö
Homework Helper
518
11
3x = arccos (1)^2
This is wrong.


cos2(3x) = 1
<=> cos 3x = +- 1
Can you do the rest?
 
  • #3
394
2
Yes, thank you. I see what I did now & this helps.
 

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