Find the equation of the tangent plane to z=x2+y2z = x^2 + y^2z=x2+y2 at the point (1,1,2)(1, 1, 2)(1,1,2).
z=2x+2y−2z = 2x + 2y - 2z=2x+2y−2
z=x+y−1z = x + y - 1z=x+y−1
z=4x+4y−2z = 4x + 4y - 2z=4x+4y−2
z=2x+2y+2z = 2x + 2y + 2z=2x+2y+2