11 Determine whether the following linear transformations are onto or one-to-one. 11 1. T(X1, X2, x3, x4) = (x1 + 2x2 2x3 + x4, 3x2 + 4x3, x1 + 2x3 + x4). 2. T(X1, X2, X3) = (x1 + x2, - X1 + 2x2 + 4x3,2x1 - x2 + 3x3,5x1 + 3x2 + 6x3). 3. T(x, y) = (x cos - y sin 0, x sin + y cos 6), where 0 e R is an angle in radians