Q. Find the maximum value of the function f(x)=−1.6x2+20.1x−71 to the nearest hundredth.Answer:
Find Vertex: To find the maximum value of the quadratic function f(x)=−1.6x2+20.1x−71, we need to find the vertex of the parabola. Since the coefficient of x2 is negative, the parabola opens downwards, and the vertex will give us the maximum value. The x-coordinate of the vertex can be found using the formula −2ab, where a is the coefficient of x2 and b is the coefficient of x.
Calculate x-coordinate: First, we calculate the x-coordinate of the vertex using the formula −2ab. Here, a=−1.6 and b=20.1. x-coordinate of vertex = −2ab = −2×−1.620.1 = −−3.220.1 = 6.28125
Calculate y-coordinate: Now that we have the x-coordinate of the vertex, we can find the y-coordinate, which is the maximum value of the function, by substituting x=6.28125 into the function f(x).f(6.28125)=−1.6(6.28125)2+20.1(6.28125)−71
Perform Calculations: Let's perform the calculations:f(6.28125)=−1.6(39.452515625)+126.25−71f(6.28125)=−63.123225+126.25−71f(6.28125)=63.126775
Recalculate f(6.28125): We will redo the calculation for f(6.28125) correctly: f(6.28125)=−1.6(6.28125)2+20.1(6.28125)−71f(6.28125)=−1.6×39.452515625+126.2503125−71f(6.28125)=−63.123225+126.2503125−71f(6.28125)=63.1270875−71f(6.28125)=−7.8729125 Since we are looking for the maximum value, we need to round this to the nearest hundredth.
Round to Nearest Hundredth: The maximum value of the function, rounded to the nearest hundredth, is −7.87.
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