Happy New Year!
There is a question on my exercise book that:
The slopes of lines L1 and L2 are the roots of the equation 6 x^2 - 5x - 1 = 0
If a is the acute angle between L1 and L2, find the value of tan a .
The answer I 've calculated is 7 / 5.
But the book says that it should be 1/7.
How can I get this or it's the mistake of the book?