Question

2sqrt2costheata+4=6

Is this pi/4 and 7pi/4

Answer 1

\[2\sqrt{2}\cos \theta+4=6\]

Answer 2

we have to subtract 4 from both sides first

Answer 3

I did that then I divided by 4

Answer 4

no, please after that subtraction, you have to divide by 2*sqrt(2)

Answer 5

I meant 2 my bad

Answer 6

now divide by sqrt(2)

Answer 7

you should get this:
\[\cos \theta = \frac{1}{{\sqrt 2 }}\]

Answer 8

Is this answer then pi/4 and 7pi/4?

Answer 9

ok!

Answer 10

hmmm

Answer 11

actually need to redo that one.. one sec

Answer 12

have a few typos darn it

Answer 13

\(\bf 2\sqrt{2}cos (\theta)+4=6\implies 2\sqrt{2}cos (\theta)=2
\\ \quad \\
cos (\theta)=\cfrac{\cancel{2}}{\cancel{2}\sqrt{2}}\implies cos^{-1}[cos(\theta)]=cos^{-1}\left( \cfrac{1}{\sqrt{2}} \right)
\\ \quad \\
\theta=cos^{-1}\left( \cfrac{1}{\sqrt{2}} \right)\)

Answer 14

ok! your solution is right for the first round angle @minisweet4