f(x)=x²+n*x+(m-1-n)

m = 2 (slider from -5 to 5, step 1)
t = 8 (slider from -10 to 10, step 1)
f(x) = x^(2) + m * x + t - 1 - m
text4: "f(x)=" + (LaTeX[f]) + ""
A: (1, t)