Help with precal please!
okay?
\[2\cos ^{2}x = 1\]
yes it's solving trigonometric equations
solve for cosx
\[\left(\begin{matrix}2Cos ^{2}x \\ 2\end{matrix}\right) = \frac{ 1 }{ 2 }\]
\[Cos^2x = \frac{ 1 }{ 2 }\]
\[x = \cos^{-1} (\frac{ 1 }{ 2 })\]
Then using a calculator or something do the right side of the last step
you're just supposed to simplyfy it down to cosx = whatever and then you go to the unit circle and use that to determine where that value occurs for cos and that's your answer
oh shot I missed cos^2, ignore the last step
Oh I see so in the end you have \[Cosx = \sqrt{\frac{ 1 }{ 2 }}\]
I got it down to cos ^2x = 1/2 but from there you would have to square both sides and square root of 1/2 isn't on the unit circle
Any ideas?
I'm looking through my notes, I just did this unit
I'm pretty sure it's 60 degrees but I want to make sure
Ok
Actually I don't know.... I could try messaging someone to help you out.
That would be great. 60 degrees is 1/2 but i need square root of 1/2 which isn't an option so I messed up somewhere
yeah
@TheSmartOne
Join our real-time social learning platform and learn together with your friends!