Displaying ∂u/∂t but only get ∂u() and displaying 2nd order ode

[Anthony The Koala]

Thank you for your time.
Background information
Using the top row button, 3rd from the left one can select a set of templates such as:numerator/denominator a number raised to a power, as well as ∂u/∂t - the u and t are squares you inset in the squares.

Before I have been able to display in the home screen ∂u/∂t

I want to display

∂u/∂t

BUT now only able to display

∂()

How do I display ∂u/∂t?

How do I display ∂²u/∂x²

Thank you
Anthony, Sydney

[gehakte_bits]

Your 'Entry' has changed to Algebraic.
So set Entry:=0, or use the Home Settings to change to 'Textbook' or RPN

[Anthony The Koala]

It is inexplicable but I managed to be able to express the numerator and demominator of a partial derivative.

Nevertheless, if there is a method to get a numerator and denominator such as
∂u/∂x instead of ∂() I would be happy.

I managed to get a double derivative such as ∂²u/∂x²
Example
Suppose we have a 2nd order ode of
y"+3*y'=0
A solution is:
y = C1 + C2*e^(-3x)

In the prime:
desolve(∂(∂u/∂x)∂x+3*∂u/∂x=0,x,y)
G_0*e^(-3x) + G_1

To achieve ∂(∂u/∂x)∂x
1. Press the top row, third button from the left select ∂ /∂.
2. On the numerator of ∂ /∂ place ∂u/∂x. On the denominator of ∂ /∂ place an x to finally make it
∂(∂u/∂x)∂x

Thank you
Anthony, Sydney