# Trig Help ## Recommended Posts I have procrastinated my Trig HW and I did what I knew but there are a few problems that I am stumped on and the Book does not do a great job on explaining it... So I shall see if you guys/girls can help me out.

Directions: Solve each equation on the interval 0 is less than or equal to theta(Symbol) < 2Pie.

11. 2Sin(squared)Theta - 1 = 0

13. Sin(3Theta) = -1

17. Sec 3Theta/2 = -2

23. 4Sec(Theta) + 6 = -2

-I got this down to: Sec(Theta) = -2

25. 3(Root 2)Cos(Theta) + 2 = -1

-I got this down to: Cos(Theta) = -3/ 3(Root2)

27. Cos(2(Theta) - Pie/2) = -1

29. Tan((Theta)/2 + Pie/3) = 1

I am sorry to put this onto you to help but yeah I just do not understand these problems but I got all the others...

If you are able to provide assistance I would appreciate like a tutorial on it to help myself... Thank you in advance.

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• Created I have procrastinated my Trig HW and I did what I knew but there are a few problems that I am stumped on and the Book does not do a great job on explaining it... So I shall see if you guys/girls can help me out.

Directions: Solve each equation on the interval 0 is less than or equal to theta(Symbol) < 2Pie.

11. 2Sin(squared)Theta - 1 = 0

13. Sin(3Theta) = -1

17. Sec 3Theta/2 = -2

23. 4Sec(Theta) + 6 = -2

-I got this down to: Sec(Theta) = -2

25. 3(Root 2)Cos(Theta) + 2 = -1

-I got this down to: Cos(Theta) = -3/ 3(Root2)

27. Cos(2(Theta) - Pie/2) = -1

29. Tan((Theta)/2 + Pie/3) = 1

I am sorry to put this onto you to help but yeah I just do not understand these problems but I got all the others...

If you are able to provide assistance I would appreciate like a tutorial on it to help myself... Thank you in advance.

ummm......just looking at the header made my brain hurt.... brain exploded when i saw equation :( .....so some one tell when this place became the homework nanny
##### Share on other sites Too busy to answer them but will tell you a few things. You'll need to use some identities to solve some of them. (for example the sin^2x and and cos2x).

The sec one should be easy. Secx is 1/cosx. Which implies the cosx is -0.5. Then solve as per usual...

What method you using? CAST?

##### Share on other sites Hmmm this place never turned into the Homework place because no one asks :rolleyes: lol so I did.

@Lite: Yeah I know it has to do with those identities and I applied the ones I know and the method, I am not sure what CAST is... So I am not even sure which method my Teacher is teaching =X

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