10.5B Notes ? Rotation of Axes The general equation of the second degree in two variables may be written where A, B, C, D, E and F are real coefficients and not all of A, B or C are zero. We can transform this equation into an equation in terms of X and Y by rotating the axes through an appropriate angle ?. To find the angle that works substitute for x and y using the rotation formulas. x = X cos ? ? Y sin ?, y = X sin ? + Y cos ? in terms of X and Y is Expanding this and collecting like terms, (which is quite a job), we obtain an equation of the form ?.. Where In order to eliminate the XY-term, we need to choose so that . That is or equivalently . Note: Don?t forget your half angle formulas for sine and cosine. ?
TRIG rotated axis proof
Primary tabs
10.5B Notes ? Rotation of Axes The general equation of the second degree in two variables may be written where A, B, C, D, E and F are real coefficients and not all of A, B or C are zero. We can transform this equation into an equation in terms of X and Y by rotating the axes through an appropriate angle ?. To find the angle that works substitute for x and y using the rotation formulas. x = X cos ? ? Y sin ?, y = X sin ? + Y cos ? in terms of X and Y is Expanding this and collecting like terms, (which is quite a job), we obtain an equation of the form ?.. Where In order to eliminate the XY-term, we need to choose so that . That is or equivalently . Note: Don?t forget your half angle formulas for sine and cosine. ?
Need Help?
We hope your visit has been a productive one. If you're having any problems, or would like to give some feedback, we'd love to hear from you.
For general help, questions, and suggestions, try our dedicated support forums.
If you need to contact the Course-Notes.Org web experience team, please use our contact form.
Need Notes?
While we strive to provide the most comprehensive notes for as many high school textbooks as possible, there are certainly going to be some that we miss. Drop us a note and let us know which textbooks you need. Be sure to include which edition of the textbook you are using! If we see enough demand, we'll do whatever we can to get those notes up on the site for you!