extreme f(x)=129x-0.5x^4+900

解答

极值点

f (x) = 129 x - 0.5 x^{4} + 900

极大值 (3 \frac{129}{2}, 1288.00519 \dots)

求解步骤

f^{'} (x) = - 2 x^{3} + 129

Find intervals:

递增

: - \infty < x < 3 \frac{129}{2},

递减

: 3 \frac{129}{2} < x < \infty

将

x = 3 \frac{129}{2}

代入

129 x - 0.5 x^{4} + 900 : 1288.00519 \dots

极大值 (3 \frac{129}{2}, 1288.00519 \dots)

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