multivariable-gradient

f(x, y) = x^(2) + y^(2)
eq1: y = 0
eq2: x = 1
P1: (1, 0, f(1, 0))
a = CurveCartesian(1, v, f(1, v), v, -10, 10)
b = CurveCartesian(i, 0, f(i, 0), i, -10, 10)
g = Tangent(P1, b)
h = Tangent(P1, a)