Cot2theta= cot^2theta-1 over 2cottheta Choose the sequence of steps that vary the ...
- Thread starter Nasyad
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What are your thoughts? What have you done so far? Please show us your work even if you feel that it is wrong so we may try to help you. You might also read
http://www.freemathhelp.com/forum/threads/78006-Read-Before-Posting
I assume you mean
Prove
(1) \(\displaystyle cot(2\theta)\, =\, \frac{cot^2(\theta)-1}{2\, cot(\theta)}\)
and
Solve for \(\displaystyle \theta\)
(2) \(\displaystyle 3\, sqrt{2}\, cos(\theta)\, +\, 1\, =\, -2\)
If that is not the case, please use grouping symbols for your equations to make the plainer and restate the problem as to what the actual questions are.
If it is the case, for (1) I would start with changing the initial cot(\(\displaystyle 2\, \theta\)) into sines and cosines, use the sum formulas for the sine and cosine, and proceed from there. For (2) I would first simplify the equation, then remember that cos(-x)=cos(x) and the cosine has a period of 2\(\displaystyle \pi\).
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What "sequences of steps" were you given, from which you are supposed to choose? What are your thoughts? Where are you stuck?
They were supposed to explain their notation to you! The "with a line under it" inequality symbols are the "or equal to" inequalities. So:
. . . . .< : "less than"
. . . . .< : "less than or equal to"
. . . . .> : "greater than"
. . . . .> : "greater than or equal to"
By the way, in the instructions for the first equation, was "vary" maybe meant to say "verify"? Thank you!
