a = 1 (slider from -10 to 10, step 0.1)
b = 0 (slider from -10 to 10, step 0.1)
c = 0 (slider from -10 to 10, step 0.1)
d: y = a * x^(2) + b * x + c
text2: "y=" + (LaTeX[a]) + "x^2 + " + (LaTeX[b]) + " x + " + (LaTeX[c]) + ""