If f (x) = 2x & # 178; - MX- If the function f (x) = 2x & # 178; - MX-3 is an increasing function when x ∈ [2, positive infinity] and a decreasing function when x belongs to (negative infinity, - 2), then f (1) is equal to? And solved by the most basic method,
analysis
A function is a quadratic function with an opening up
Your question is wrong, it should be (- Infinity 2]
therefore
x=-b/2a=m/4=2
m=8
f(x)=2x²-8x-3
f(1)=2-8-3
=-6-3
=-9
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