Question: rumus cepat geometric transformation
1. **Stating the problem:** We want to understand the quick formulas (rumus cepat) for geometric transformations.
2. **Types of geometric transformations:** The main types are translation, rotation, reflection, and dilation (scaling).
3. **Translation formula:** Moves a point $(x,y)$ by $(a,b)$ to $(x',y')$:
$$x' = x + a$$
$$y' = y + b$$
4. **Rotation formula:** Rotating a point $(x,y)$ about the origin by an angle $\theta$:
$$x' = x\cos\theta - y\sin\theta$$
$$y' = x\sin\theta + y\cos\theta$$
5. **Reflection formula:** Reflecting a point $(x,y)$ about the x-axis or y-axis:
- About x-axis: $$x' = x, \quad y' = -y$$
- About y-axis: $$x' = -x, \quad y' = y$$
6. **Dilation (scaling) formula:** Scaling a point $(x,y)$ by a factor $k$ from the origin:
$$x' = kx$$
$$y' = ky$$
7. **Summary:** These formulas allow quick calculation of new coordinates after transformations.
This completes the explanation of quick formulas for geometric transformations.