Assume 命令

CAS 语法

Assume( <Condition>, <Expression> )

根据条件对表达式求值

  • Assume(a > 0, Integral(exp(-a x), 0, infinity)) 得出 1 / a .

  • Assume(x>0 && n>0, Solve(log(n^2*(x/n)^lg(x))=log(x^2), x)) 得出 {x = 100, x = n}

  • Assume(x<2,Simplify(sqrt(x-2sqrt(x-1)))) 得出 -sqrt(x - 1) + 1

  • Assume(x>2,Simplify(sqrt(x-2sqrt(x-1)))) 得出 sqrt(x - 1) - 1

  • Assume(k>0, Extremum(k*3*x^2/4-2*x/2)) 得出 \( \left\{ \left(\frac{2}{3 k}, -\frac{1}{3 k} \right)\right\} \)

  • Assume(k>0, InflectionPoint(0.25 k x^3 - 0.5x^2 + k)) 得出 \( \left\{ \left(\frac{2}{3 k}, \frac{27k^{3} - 4}{27 k^{2}} \right) \right\} \)

参见 Solve .