Question 1 Report
Express \(3x^{2} - 6x + 10\) in the form \(a(x - b)^{2} + c\), where a, b and c are integers. Hence state the minimum value of \(3x^{2} - 6x + 10\) and the value of x for which it occurs.
Express \(3x^{2}-6x+10\) as \(a(x-b)^{2}+c\).
Factor 3 from the x-terms and complete the square:
\[3x^{2}-6x+10=3(x^{2}-2x)+10=3\big[(x-1)^{2}-1\big]+10\]\[=3(x-1)^{2}-3+10=3(x-1)^{2}+7\]So \(a=3,\ b=1,\ c=7\).
Minimum value. Since \(3(x-1)^{2}\ge 0\) and is zero when \(x=1\), the least value of the expression is
\[3(0)+7=7\ \text{at } x=1\]The minimum value is \(7\), occurring at \(x=1\).
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