Toronto Math Forum
MAT244--2019F => MAT244--Test & Quizzes => Quiz-4 => Topic started by: Yiheng Bian on October 18, 2019, 08:41:21 PM
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$$
\text{The question is } 9y''+9y'-4y=0
$$
$$
9r^2+9r-4=0
$$
$$
\text{So r1}=\frac{1}{3}
$$
$$
r2=\frac{-4}{3}
$$
$$
\text{So we can get y}=c_1e^{\frac{t}{3}}+c_2e^{\frac{-4t}{3}}
$$