Sin 0 = 7/25 and cos 0 = -24/25. Find tan 0

Find parametric equations for the line tangent to the curve of intersection of the surfaces at the given point. surfaces: xsquared2plus+2yplus+2zequals=1212 yequals=33 point: left parenthesis 1 comma 3 comma five halves right parenthesis

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?