Vẽ đồ thị hàm số câu 1

To plot the graphs of the given functions, you can follow these steps:

### For part a:
**Function:** \( y = -x^2 + 3x - 2 \)

1. **Identify the type of function**: This is a quadratic function and has the general form \( y = ax^2 + bx + c \).
- Here, \( a = -1 \), \( b = 3 \), and \( c = -2 \).
2. **Vertex**: Determine the vertex using the formula \( x = -\frac{b}{2a} \).
- \( x = -\frac{3}{2 \cdot -1} = \frac{3}{2} \).
3. **Calculate y-coordinate of the vertex**: Substitute \( x = \frac{3}{2} \) into the function.
- \( y = -\left(\frac{3}{2}\right)^2 + 3\left(\frac{3}{2}\right) - 2 \).
4. **Intercepts**: Find \( x \)-intercepts by solving \( y = 0 \).
5. **Plot Points**: Choose a few values of \( x \) to calculate corresponding \( y \).

### For part b:
**Function:** \( y = 2x^3 - 8 \)

1. **Identify the type of function**: This is a cubic function.
2. **Intercept**: Set \( y = 0 \) to find \( x \)-intercepts.
- \( 2x^3 - 8 = 0 \Rightarrow x^3 = 4 \Rightarrow x = \sqrt[3]{4} \).
3. **Behavior**: Note the end behavior of cubic functions, which typically goes from the bottom left to the top right.
4. **Plot Points**: Calculate \( y \) for several values of \( x \).

### General Tips:
- Use graphing tools or software to accurately plot the functions based on the points calculated.
- Ensure to label axes and indicate key points like the vertex, intercepts, and any turning points.

Would you like assistance with specific calculations or further details on either function?