1. **State the problem:** We are given a point (-3, -4) and a radius $r=5$. We need to find the reference angle and the rotational angle for this point.
2. **Recall the formulas:**
- The reference angle is the acute angle the terminal side of the point's radius vector makes with the x-axis.
- The rotational angle (also called the standard position angle) is the angle measured counterclockwise from the positive x-axis to the point.
3. **Calculate the reference angle:**
The reference angle $\theta_{ref}$ can be found using the tangent function:
$$\tan(\theta_{ref}) = \left|\frac{y}{x}\right| = \left|\frac{-4}{-3}\right| = \frac{4}{3}$$
4. **Find $\theta_{ref}$:**
$$\theta_{ref} = \arctan\left(\frac{4}{3}\right)$$
Using a calculator or known values:
$$\theta_{ref} \approx 53.13^\circ$$
5. **Determine the quadrant:**
The point (-3, -4) lies in the third quadrant (both x and y are negative).
6. **Calculate the rotational angle:**
In the third quadrant, the rotational angle $\theta$ is:
$$\theta = 180^\circ + \theta_{ref} = 180^\circ + 53.13^\circ = 233.13^\circ$$
7. **Verify radius:**
Given $r=5$, check with Pythagoras:
$$(-3)^2 + (-4)^2 = 9 + 16 = 25$$
$$\sqrt{25} = 5$$
This confirms the radius is correct.
**Final answers:**
- Reference angle $= 53.13^\circ$
- Rotational angle $= 233.13^\circ$
Reference Rotational Angle 1E1C4A
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