Find the real root(s) of the following equation.
Question: http://img293.imageshack.us/i/78492738.jpg/
Ans: 3
F4 Math find real root(s)
2010-04-25 8:03 pm
回答 (1)
2010-04-25 8:16 pm
✔ 最佳答案
2x = 1 + (7x + 4)^0.52x - 1 = (7x + 4)^0.5
4x^2 - 4x + 1 = 7x + 4
4x^2 - 11x - 3 = 0
(4x + 1)(x - 3) = 0
x = - 1/4 or x = 3
sub x = - 1/4 to 2x = 1 + (7x + 4)^0.5 ,
LHS = - 1/2 , RHS = 5/2
LHS <> RHS
So x = 3
收錄日期: 2021-04-21 22:11:24
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100425000051KK00467