Questions: Qual das opções a seguir é o gráfico correto de
f(x) = 2x^2 + 8x - 2
Transcript text: Qual das opçōes a seguir é o gráfico correto de
\[
f(x)=2 x^{2}+8 x-2
\]
Solution
Solution Steps
Step 1: Analyze the given function
The given function is f(x) = 2x² + 8x - 2. This is a quadratic function in the form ax² + bx + c, where a = 2, b = 8, and c = -2.
Step 2: Determine the properties of the parabola
Since a = 2 > 0, the parabola opens upwards.
The y-intercept occurs when x = 0. f(0) = 2(0)² + 8(0) - 2 = -2. The parabola passes through the point (0, -2).
The x-coordinate of the vertex is given by -b/(2a) = -8/(2*2) = -2.
The y-coordinate of the vertex is f(-2) = 2(-2)² + 8(-2) - 2 = 8 - 16 - 2 = -10. So, the vertex is at (-2, -10).
Step 3: Compare with the given options
The fourth option shows a parabola that opens upwards, has a vertex at approximately (-2, -10), and a y-intercept at approximately (0, -2).
Final Answer: The fourth option is the correct graph.