e 7 : solve the following differential equation :y′′−y=0
y(x)=C1e−x+C2ex
Step 1 :Find the characteristic equation: r2−1=0
Step 2 :Find the roots: r1=−1 and r2=1
Step 3 :Write the general solution: y(x)=C1e−x+C2ex
Step 4 :y(x)=C1e−x+C2ex