Trig Question 8(c) Solution Discussion - Edexcel 6665-01 January 2011 Exam

[jsmith613]

Homework Statement

Question paper:
http://www.edexcel.com/migrationdoc...00/January 2011 - QP/6665_01_que_20110124.pdf

Mark scheme:
http://www.edexcel.com/migrationdoc...00/January 2011 - MS/6665-01-msc-20110223.pdf

For question 8(c)
would you agree that the mark scheme omits a solution
should it not be plus-minus sqrt(x²-1)

Homework Equations

The Attempt at a Solution

see header of question

 

[LCKurtz]

I would have put a $\pm$ sign on it. But one might also make the argument that the inverse function is understood to mean the principal value branch. In that case the principal value branch is usually chosen to have positive slope. Your mileage may vary.