Find the radian measure of $\theta$ if $0 \leq \theta \leq 2\pi$ and $\cos(\theta)(2\cos(\theta)-1) = 0.$ I'm very new to this topic, so what I did was to take the inverse of $\cos$ from both sides, and then you're left with $2\cos(\theta) - 1 = 1.570\,\,\, (\text{radians}).$ Then get rid of the 2 and -1: $\cos(\theta) = 0.285$. Now take the inverse from both sides again and you end up with 1.281 radians.
My calculations are probably complete B.S. Can anyone help me out here?
- Why are there more than 1 answers on my answer sheet?
- Can you please help me get the right answers?
- This is on a non calculator paper - (however my teacher admits that several questions belong in the calculator paper) - Is it likely that the question will be in the calculator paper instead, or am I just missing the big point of it all?
Thanks so much, John.