Question

find the value of θ in the equation cos2θ+sin²θ=cos³θ+3θ-6

Answer 1

i got as far as substituting the double angle formula in there and simplifying to get
cos^2x=cos^3x+3x-6
cos^2x-cos^3x=3x-6

Answer 2

yeah that is how far i got too

Answer 3

you could try solving \(u^3-u^2+3u-6=0\) and and then take the inverse cosine if you can find such a solution

Answer 4

okay
well its a multiple choice:
so x could equal
6
cos2x
x
or
2

Answer 5

then cheat
http://www.wolframalpha.com/input/?i=cos%282x%29%2Bsin^2%28x%29%3Dcos^3%28x%29%2B3x-6

Answer 6

2 it is then lol thanks!