### All SAT II Math I Resources

## Example Questions

### Example Question #1 : Coordinate Geometry

Which of the following points is in Quadrant IV on the coordinate plane?

**Possible Answers:**

Two of these points are in Quadrant IV.

**Correct answer:**

Quadrant IV consists of the points with positive -coordinates and negative -coordinates. Therefore is the correct choice.

### Example Question #1 : Parabolas And Circles

Give the axis of symmetry of the parabola of the equation

**Possible Answers:**

**Correct answer:**

The line of symmetry of the parabola of the equation

is the vertical line

Substitute :

The line of symmetry is

That is, the line of the equation .

### Example Question #1 : Parabolas And Circles

What is the center of the circle with the following equation?

**Possible Answers:**

**Correct answer:**

Remember that the basic form of the equation of a circle is:

This means that the center point is defined by the two values subtracted in the squared terms. We could rewrite our equation as:

Therefore, the center is

### Example Question #1 : Parabolas And Circles

What is the area of the sector of the circle formed between the -axis and the point on the circle found at when the equation of the circle is as follows?

Round your answer to the nearest hundreth.

**Possible Answers:**

**Correct answer:**

For this question, we will need to do three things:

- Determine the point in question.
- Use trigonometry to find the area of the angle in question.
- Use the equation for finding a sector area to finalize our answer.

Let us first solve for the coordinate by substituting into our equation:

Our point is, therefore:

Now, we need to calculate the angle formed between the origin and the point that we were given. We can do this using the inverse tangent function. The ratio of to is here:

Therefore, the angle is:

To solve for the sector area, we merely need to use our standard geometry equation. Note that the radius of the circle, based on the equation, is .

This rounds to .

### Example Question #5 : Coordinate Geometry

What is the area of the sector of the circle formed between the -axis and the point on the circle found at when the equation of the circle is as follows?

Round your answer to the nearest hundreth.

**Possible Answers:**

**Correct answer:**

For this question, we will need to do three things:

- Determine the point in question.
- Use trigonometry to find the area of the angle in question.
- Use the equation for finding a sector area to finalize our answer.

Let us first solve for the coordinate by substituting into our equation:

Our point is, therefore:

Now, we need to calculate the angle formed between the origin and the point that we were given. We can do this using the inverse tangent function. The ratio of to is here:

Therefore, the angle is:

To solve for the sector area, we merely need to use our standard geometry equation. Note that , based on the equation, is .

This rounds to .

### Example Question #1 : Coordinate Geometry

If the center of a circle is at and it has a radius of , what positive point on the does it intersect?

**Possible Answers:**

**Correct answer:**

Since you are looking for a point on the , your value will be zero.

The center of the circle is at the origin and radius is the distance from the center, so that means the point you are looking for must be points away from .

This can be two points on the but since you are looking for a positive one, your answer must be .

### Example Question #1 : Symmetry

Given a point , what is the new value if this point is flipped across the line ?

**Possible Answers:**

**Correct answer:**

The displacement between negative three and positive one is four.

This mean that after flipping the point, it must be symmetrical to its original location. The new point must also be 4 units to the right of the line.

The new point would be located at:

The answer is:

### Example Question #1 : Symmetry

Which of the following symmetries applies to the graph of the relation

?

I) Symmetry with respect to the origin

II) Symmetry with respect to the -axis

III) Symmetry with respect to the -axis

**Possible Answers:**

III only

I, II and III

II only

None of these

I only

**Correct answer:**

III only

The relation

is a circle with center and radius .

In other words, it is a circle with center at the origin, translated right units and up units (the radius is irrelevant to the question).

or

is this circle translated right zero units and up 2 units. The upshot is that the circle moves along the -axis only, and therefore is symmetric with respect to the -axis, but not the -axis. Also, as a consequence, it is not symmetric with respect to the origin.

### Example Question #1 : Transformations

Reflect the point across the line and then across the origin.

**Possible Answers:**

**Correct answer:**

Reflecting the point across the vertical line will only change the x-value, but not the y-value.

The point after this reflection is:

Rotating this point across the origin will swap the x and y-values.

The new point is:

### Example Question #1 : Coordinate Geometry

Let . If is equal to when flipped across the x-axis, what is the equation for ?

**Possible Answers:**

**Correct answer:**

When a function is flipped across the x-axis, the new function is equal to . Therefore, our function is equal to:

Our final answer is therefore

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