Can someone please help me. ILL GIVE BRAINLIEST TO THE RIGHT ANSWER!!

Letter A

because we should add the two smaller number in the radical and if the sum equals to the other one. Then, it is a right triangle

We're going to assume that the solution is a quadratic polynomial, since we have the sum of the function and its derivative adds up to . So let 
Plug all these into the given DE to get

or


From the above equation the left hand side should have a coffienet of 4 for , and all other coffienents must be 0. That is
 and .

You can easily solve the system above and find  and .

Thus