My result is 13.1243 degrees.
You are correct.
The book has a typo.
I am getting the wrong answer for the following question: a diagram is attached.
A hillside forms a plane surface inclined at to the hoizontal. A straight path up the hillside makes an angle of with the line of greatest slope. Find to the nearest degree, the inclination of the path to the horizontal.
I have: h = PQ = RS
tan 25 = h / OS
OS = h / tan 25
cos 60 = OS/OQ
OQ = OS / cos 60.
OQ = h /(tan 25. cos 60)
To the nearest degree this is 13.
The answer I have in my maths book is 12 degrees.
So, dear friends, am I wrong or is the book wrong?