List all x values where the graph of f(x) has vertical tangents

goo.gl/photos/iPu1SHA8yyBFTcZj6

3 answers

At first I said x=-3 but that is a vertical asymptote, not a vertical tangent. Where does this graph have vertical tangents in this case?
looks to me like there is a vertical tangent at x = 2pi/3
Or near x=2, that was pretty easy, can't believe I didn't spot it at first