12) Find the complete integral of the PDE p²+q²=1
11)Solve the PDE (x+y²)p+yq=z+x².
10)Find the complete integral of the PDE yq+3xp=2(z-y²p²).
9) Eliminate the arbitrary constants a and b from the equation (x-a)²+(y-b)²+z²=2019 to obtain the partial differential equation.
8)Solve (D²+3DD'+2D'^2)z=x cos y+e^x+y, Where D=∂\∂x and D'=∂\∂y.
7)Find the integral surface of x(y²+z)p-y(x²+z)q=(x²-y²)z through the curve x+y=0,z=1.
6)If L{f(t)}= e^{-2s}+4/s(2s²+3s+5), then find lim t→∞ f(t)
5)Solve ∫0^t y''(τ)y'(t-τ)dτ=y(t),y(0)=y'(0)=20
4)Define Laplace transform and find Laplace transform of the periodic function f(t) =t,0≤t≤2 and f(t+2)=f(t)
3) Find the Laplace transform of 1-e^{-2t}/t