posted by Joanie .
Problem: Identify the conic from the equation 13x^2-6(sq.rt.6)xy+7y^2-16=0
I have to choose from the following four answers:
hyperbola (angle of rotation 45)
hyperbla (angle of rotation 60)
ellipse (angle of rotation 90)
ellipse (angle of rotation 30)
I used the discriminant (-148) is less than 0--equation on an ellipse and A does not equal C.
I am using the formula tan2theta=B/A-C to find the angle of rotation.
tan2theta = -6(dq.ft.6)/13-7 = -6(sq.rt.6)/6 =-(sq.rt. 6)
Where have I gone wrong finding the angle of rotation? I have my calculator set to degrees.
Thanks for helping!