Alot
One could be x=6 y=0
<span>C) Ro 270 degree (anticlockwise)
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You can use the identity

The sign is negative because the angle is in the 3rd quadrant.
This corresponds to ...
a. -(4√17)/17
36+54v
Multiply 6 with both 6 and 9v
If two planes are perpendicular, they intersect. if two planes are parallel, they will never touch. hope this helps