ECAT · Mathematics · 9 questions
Name: ____________________ Date: ____________
What is the distance between the points (1, 2) and (4, 6)?
What is the slope of the line through (1, 2) and (3, 8)?
Which is the equation of a circle with centre at the origin and radius 5?
What is the midpoint of the points (2, 4) and (6, 10)?
What is the dot product of the vectors (1, 2, 3) and (4, -5, 6)?
What is the magnitude of the vector (3, 4)?
What is i x j, the cross product of the unit vectors i and j?
What is the focus of the parabola y² = 8x?
Two vectors are perpendicular when their dot product is:
1. A, 2. A, 3. D, 4. D, 5. D, 6. C, 7. B, 8. A, 9. B
Distance = sqrt(3² + 4²) = sqrt(25) = 5.
Slope = (8 - 2) / (3 - 1) = 6 / 2 = 3.
A circle with centre (0, 0) and radius r has the equation x² + y² = r².
The midpoint is ((2 + 6) / 2, (4 + 10) / 2) = (4, 7).
1 x 4 + 2 x (-5) + 3 x 6 = 4 - 10 + 18 = 12.
The magnitude is sqrt(9 + 16) = 5.
By the right-hand rule, i x j = k.
Comparing with y² = 4ax gives 4a = 8, so a = 2 and the focus is (2, 0).
a . b = |a||b| cos(theta), which is 0 exactly when the angle is 90 degrees.