Wei Li

52 Reputation

2 Badges

15 years, 210 days

MaplePrimes Activity


These are questions asked by Wei Li

restart
assume(c, 'real')
solve(272*c^3-213*c^2+52*c-4 > 0, c)
but i get the result:

why not the desired result?

{c < -(1/1632)*(101709+(3264*I)*sqrt(1407))^(1/3)-979/(544*(101709+(3264*I)*sqrt(1407))^(1/3))+71/272-(1/2*I)*sqrt(3)*((1/816)*(101709+(3264*I)*sqrt(1407))^(1/3)-979/(272*(101709+(3264*I)*sqrt(1407))^(1/3))), -(1/1632)*(101709+(3264*I)*sqrt(1407))^(1/3)-979/(544*(101709+(3264*I)*sqrt(1407))^(1/3))+71/272+(1/2*I)*sqrt(3)*((1/816)*(101709+(3264*I)*sqrt(1407))^(1/3)-979/(272*(101709+(3264*I)*sqrt(1407))^(1/3))) < c}, {(1/816)*(101709+(3264*I)*sqrt(1407))^(1/3)+979/(272*(101709
here is the matrix,for example, result:=Matrix(2, 2, {(1, 1) = 4*c-4, (1, 2) = -2*c+3, (2, 1) = -2*c+3, (2, 2) = 4*c-15/4}) for what region of c, this matrix is positive definite? I typed the following in Maple, > IsDefinite(result); / 2 \ 0 <>
Dear sir: I have a question, I am not sure if the Maple can solve it. For a n*n matrix such as: ------------------------------- X_1 x_2 x_3 ... x_n 1 0 0 ... 0 0 1 0 ... 0 ... 0 0 0 ... 1 -------------------------------- Where n is a constant (n is a abstract number, not concrete as 3 or 4), the same is for x_1,x_2... I want to calculate its inverse of this matrix! I am not sure whom I should ask for help! Please give me some instructions! Yours sincerely;
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