Differential Equation: 1st-Order in Time, 2nd-Order in Space

[saravanan13]

what is the order of differential equation which contains first order in time and second order in space derivative?

 

[elibj123]

it will be the order of the highest derivative (doesn't matter in respect to what variable).
In your case, it's a second order pde

 

[HallsofIvy]

Although it would also be perfectly acceptable to say "The differential equation is of second order in x and first order in t".

 

[elibj123]

It is a more specific classification

But in respect to how you solve the PDE, it's only important what's the highest order.

In this matter, how would you classify $$u_{xt}+blabla=0$$, first order in time and space, or second-order in both?