# Question:another expression Maple can't simplify

## Question:another expression Maple can't simplify

Maple 2020

I think Maple's simplify could need much more improvement.

Here is another example, which I can't get Maple to simplify to zero for positive x, when it is clearly zero there

```restart;
ode:=x = (diff(y(x),x)^2+1)^(1/2)*diff(y(x),x);
mysol:=y(x)=_C1+int(  sqrt(-2+2*sqrt(4*a^2+1))/2,a=0..x);
check:=odetest(mysol,ode);```

The above is zero for x>0

But I tried every assumption or option on it, and it will not give zero.

```simplify(check) assuming x>0;
simplify(check,symbolic);
simplify(check,symbolic,sqrt) assuming x>0;
simplify(check,sqrt) assuming x>0;
simplify(check,power) assuming x>0;
etc...```

Here it is in Mathematica

```ClearAll[x];
check = x - (Sqrt[2 + 2 Sqrt[4 x^2 + 1]]) (Sqrt[-2 + 2 Sqrt[4 x^2 + 1]])/4;
Simplify[check, Assumptions -> x > 0]```

Why Maple can't simplify this to zero?  Is there some other specific trick one must use each time?

Maple 2020.2 on windows 10

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