Use Euler's Method with $\displaystyle h = 0.2$ to approximate the solution to the initial value problem:
$\displaystyle y' = -20y$
$\displaystyle y(1) = 3$
at
$\displaystyle x = 1, 1.2, 1.4$
Euler's method for the numerical integration of an ODE IVP uses the stepping formula:
$\displaystyle y(t+ \delta t)=y(t)+\delta t\times y'(t)$
You are given $\displaystyle y(1)$ and that $\displaystyle \delta t =0.2$, so immediately the stepping formula will tell you the value at $\displaystyle t=1.2$, then applying it again from $\displaystyle t=1.2$ and the value of $\displaystyle y(1.2)$ you found from the first step, it will give the value at $\displaystyle t=1.4$.
CB
Yeah. I knew the solution to the equation already.
Thanks for the help. I appreciate it. And this was a test question... I just wanted to get clarification on the answer.
But the next question was the same thing with the Improved Euler's method and I got a much better answer, which would mean that bigger values of h are allowed in the Improved method as opposed to the classical method.