Answer:
[tex]y(x)=6+9x[/tex]
Step-by-step explanation:
Given differential equation, [tex]y''=0[/tex]
Characteristic equation is given by [tex]m^2=0[/tex]
[tex]\Rightarrow m=0,0[/tex].
Differential equation have repeated roots and solution of differential equation is [tex]y(x)=C_1+C_2x[/tex].............................(1)
Initial conditions are [tex]y(0)=6,y'(0)=9[/tex]
Plugging first condition in equation (1),
[tex]6=C_1+C_2(0)[/tex]
[tex]C_1=6[/tex]
Equation (1) becomes
[tex]y(x)=6+C_2x[/tex]............................(2)
differentiate equation (2) with respect to 'x',
[tex]y'(x)=C_2[/tex]
Plugging second condition,
[tex]C_2=9[/tex]
Hence, [tex]y(x)=6+9x[/tex]