Thank you for posting your question!
When you have a quadratic function like this the optimal value is going to happen at the vertex, so you want to find that by taking
t = -b/2a = -50 / (2*-16) = -50 / -32 = 1.5625 seconds
To get the maximum height then you want to plug that value back into the original function
h(1.5625) = -16(1.5625)^2 + 50(1.5626) + 10
=-39.0625 + 78.125 + 10
=49.0625 feet
For domain and range you just want to think in terms of values that are possible … so since domain is a unit of time it can’t be less than 0, which means that the range cannot be below 10. I hope that helps! :)