### All Calculus 2 Resources

## Example Questions

### Example Question #1 : Polar Calculations

Convert the polar coordinate equation into its rectangular equivalent, and simplify.

**Possible Answers:**

None of the other answers

**Correct answer:**

The polar to rectangular transformation equations are . By substituting these into our given equation we get .

Adding to both sides, then we get .

### Example Question #2 : Polar Calculations

Convert the following polar coordinates of the form into Cartesian coordinates of the form :

**Possible Answers:**

**Correct answer:**

In order to convert the given polar coordinates into Cartesian coordinates, we must remember our formulas for x and y in terms of r and :

The problem tells us r and , so all we must do to convert these coordinates is plug them into the formulas above:

So we can see from our conversion that the given polar coordinates are expressed as in Cartesian coordinates.

### Example Question #3 : Polar Calculations

Convert to Cartesian coordinates.

**Possible Answers:**

**Correct answer:**

The following formulas will convert polar coordinates to Cartesian coordinates.

We are given the polar coordinate, which is in form. Plug the coordinate into the formulas and solve for x and y.

The Cartesian coordinate form is .

### Example Question #4 : Polar Calculations

Given the Cartesian coordinate , what is in the polar form ?

**Possible Answers:**

**Correct answer:**

The formula to find theta in polar form is:

Plug in the Cartesian coordinates into the equation.

However, this angle is located in the fourth quadrant and is not in the right quadrant. Add radians to get the correct angle since the Cartesian coordinate given is located in the second quadrant.

### Example Question #5 : Polar Calculations

Tom is scaling a mathematical mountain. The mountain's profile can be described by between and . Tom climbs from to the peak of the mountain. How far did he climb? You'll need an equation solver for certain parts of the problem. Round everything to the nearest hundredth.

**Possible Answers:**

**Correct answer:**

This is a two step problem. First step is to maximize the function to find the peak of the mountain. The next step is to use the arc length formula to find the distance he climbed.

To maximize, we'll take a derivative and set it equal to zero.

.

Setting this equal to zero, we get .

The derivative is positive prior to this value and negative after, so it is a max. We now must take the arc length from to .

The formula for arc length is

.

For this case, the integral becomes

.

This will give us . No units were given in the problem, so leaving the answer unitless is acceptable.

### Example Question #6 : Polar Calculations

Find the length of the polar valued function from to .

**Possible Answers:**

**Correct answer:**

Recall the formula for length in polar coordinates is given by

.

We were given the formula

.

In our case, this translates to

.

### Example Question #6 : Polar Calculations

Convert to Cartesian coordinates.

**Possible Answers:**

**Correct answer:**

Write the formulas to convert from polar to Cartesian.

The and values are known. Substitute both into each equation and solve for and .

The Cartesian coordinates are:

### Example Question #7 : Polar Calculations

Convert to Cartesian coordinates and find the coordinates of the center.

**Possible Answers:**

**Correct answer:**

Write the conversion formulas.

Notice the term. If we multiplied by on both sides of the equation, we will get:

Substitute this back into the first equation.

Add on both sides.

Complete the square with the terms.

This would then become:

This is a circle centered at with a radius of 4.

The answer is:

### Example Question #8 : Polar Calculations

Convert to Cartesian coordinates.

**Possible Answers:**

**Correct answer:**

When converting from polar to Cartesian coordinates, we must use the formulas

the values and are given, so we can calculate that

and

So the Cartesian coordinate form is

### Example Question #9 : Polar Calculations

Determine the equation in polar coordinates of

**Possible Answers:**

**Correct answer:**

can be immediately transformed into polar form by:

.

Dividing by ,

Dividing both sides by