Q. The function f is defined as f(x)=3x−2.What is the x-coordinate of the point on the function's graph that is closest to the origin?
Define Distance Formula: To find the point on the graph of the function f(x)=3x−2 that is closest to the origin, we need to minimize the distance from any point (x,f(x)) on the graph to the origin (0,0). The distance D between the point (x,f(x)) and the origin (0,0) can be found using the distance formula: D=((x−0)2+(f(x)−0)2).
Substitute f(x): Substitute f(x) with 3x−2 into the distance formula: D=x2+(3x−2)2.
Expand Expression: Expand the expression inside the square root: D=x2+(9x2−12x+4).
Combine Like Terms: Combine like terms inside the square root: D=10x2−12x+4.
Minimize Expression: To find the minimum distance, we can minimize the expression inside the square root since the square root function is increasing. This is equivalent to minimizing the quadratic expression 10x2−12x+4. To find the minimum of a quadratic function, we can use the vertex formula x=−2ab, where the quadratic is in the form ax2+bx+c.
Apply Vertex Formula: Apply the vertex formula to the quadratic expression 10x2−12x+4. Here, a=10 and b=−12. So, x=−(−12)/(2⋅10)=12/20=0.6.
Find x-coordinate: The x-coordinate of the point on the graph of the function that is closest to the origin is 0.6. This is the final answer.
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