How do I solve a Turning Point?

Can any one determine the co-ordinate of B please (with working)

UT | Flickr - Photo Sharing!

- March 6th 2013, 03:24 PMTechWizNoHelp determining a 2nd turning point in a curve (Cubic graph)
**How do I solve a Turning Point?**

Can any one determine the co-ordinate of B please (with working)

UT | Flickr - Photo Sharing! - March 6th 2013, 03:41 PMPlatoRe: Help determining a 2nd turning point in a curve (Cubic graph)
- March 6th 2013, 09:08 PMTechWizNoRe: Help determining a 2nd turning point in a curve (Cubic graph)
Please show working