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受欢迎的代数 >

0=255-21t-16t^2

解答

0 = 255 - 21 t - 16 t^{2}

解答

t = - \frac{21 + 16761}{32}, t = \frac{16761 - 21}{32}

+1

十进制

t = - 4.70200 \dots, t = 3.38950 \dots

求解步骤

0 = 255 - 21 t - 16 t^{2}

交换两边

255 - 21 t - 16 t^{2} = 0

改写成标准形式

a x^{2} + b x + c = 0

- 16 t^{2} - 21 t + 255 = 0

使用求根公式求解

t_{1, 2} = \frac{- ( - 21 ) \pm ( - 21 ) ^{2} - 4 ( - 16 ) \cdot 255}{2 ( - 16 )}

(- 21)^{2} - 4 (- 16) \cdot 255 = 16761

t_{1, 2} = \frac{- ( - 21 ) \pm 16761}{2 ( - 16 )}

将解分隔开

t_{1} = \frac{- ( - 21 ) + 16761}{2 ( - 16 )}, t_{2} = \frac{- ( - 21 ) - 16761}{2 ( - 16 )}

t = \frac{- ( - 21 ) + 16761}{2 ( - 16 )} : - \frac{21 + 16761}{32}

t = \frac{- ( - 21 ) - 16761}{2 ( - 16 )} : \frac{16761 - 21}{32}

二次方程组的解是:

t = - \frac{21 + 16761}{32}, t = \frac{16761 - 21}{32}

作图

流行的例子

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