Answer the following:

(a) Find an angle between [tex]0[/tex] and [tex]2 \pi[/tex] that is coterminal with [tex]\frac{33 \pi}{10}[/tex].

(b) Find an angle between [tex]0^{\circ}[/tex] and [tex]360^{\circ}[/tex] that is coterminal with [tex]930^{\circ}[/tex].

Give exact values for your answers.



Answer :

Sure, let's solve these problems step-by-step:

### (a) Find an angle between [tex]\(0\)[/tex] and [tex]\(2\pi\)[/tex] that is coterminal with [tex]\(\frac{33\pi}{10}\)[/tex].

1. Understanding Coterminal Angles:
An angle is coterminal with another if they share the same terminal side when drawn in standard position. Coterminal angles can be found by adding or subtracting full rotations ( [tex]\(2\pi \)[/tex] radians) from the given angle.

2. Given Angle:
[tex]\[\frac{33\pi}{10}\][/tex]

3. Convert the Given Angle:
Let's reduce [tex]\(\frac{33\pi}{10}\)[/tex] to an angle within the range [tex]\(0\)[/tex] to [tex]\(2\pi\)[/tex].

[tex]\[ \frac{33\pi}{10} \quad \text{is more than } 2\pi \; (\approx 6.2832) \][/tex]

4. Subtract a Full Rotation:
[tex]\[ \frac{33\pi}{10} - 2\pi \times k \quad \text{where } k \text{ is an integer} \][/tex]

Since [tex]\(\frac{33\pi}{10}\)[/tex] is less than [tex]\(4\pi \)[/tex], we need to subtract only one [tex]\(2\pi\)[/tex] rotation:
[tex]\[ \frac{33\pi}{10} - 2\pi = \frac{33\pi}{10} - \frac{20\pi}{10} = \frac{13\pi}{10} \][/tex]

Here, [tex]\(\frac{13\pi}{10}\)[/tex] is already within the range [tex]\(0\)[/tex] to [tex]\(2\pi\)[/tex].

5. Coterminal Angle:
[tex]\[ \boxed{\frac{13\pi}{10}} \][/tex]

### (b) Find an angle between [tex]\(0^{\circ}\)[/tex] and [tex]\(360^{\circ}\)[/tex] that is coterminal with [tex]\(930^{\circ}\)[/tex].

1. Understanding Coterminal Angles:
Similarly, for degrees, an angle is coterminal if it is the same as the given angle plus or minus multiples of [tex]\(360^\circ\)[/tex] (a full rotation).

2. Given Angle:
[tex]\(930^\circ\)[/tex]

3. Convert the Given Angle:
Let's reduce [tex]\(930^\circ\)[/tex] to an angle within the range [tex]\(0^\circ\)[/tex] to [tex]\(360^\circ\)[/tex].

4. Subtract Full Rotations:
[tex]\[ 930^\circ \mod 360^\circ \][/tex]

This means we subtract multiples of [tex]\(360^\circ\)[/tex] until the result is within [tex]\(0^\circ\)[/tex] to [tex]\(360^\circ\)[/tex].

[tex]\[ 930^\circ - 2 \times 360^\circ = 930^\circ - 720^\circ = 210^\circ \][/tex]

Here [tex]\(210^\circ\)[/tex] is already within the range [tex]\(0^\circ\)[/tex] to [tex]\(360^\circ\)[/tex].

5. Coterminal Angle:
[tex]\[ \boxed{210^\circ} \][/tex]

So, the final answers are:
- (a) [tex]\(\frac{13\pi}{10}\)[/tex]
- (b) [tex]\(210^\circ\)[/tex]