Q: (LU decomposition) Find the LU decomposition of A = [-3 2 5
1; 12 -4 -20 -2; -6 0 15 1; -9 6 35 4]. You can use the compact
method which works within a single matrix or you can build L and U
separately. State L and U explicitly, and verify (in Matlab) that A
= L*U. Hint: Matlab's built-in lu function isn't useful, since it
pivots.
Solve the following set of equations with LU factorization with
pivoting:
3x1 -2x2 + x3 = -10
2x1 + 6x2- 4x3 = 44
-8x1 -2x2 + 5x3 = -26
Please show all steps
4. (Applying LU and LUP decompositions) In this problem, we'll
use the LU/LUP decomposition to solve a linear system of
equations.
a) For A = [12 -8 13 -1 13;14 11 -5 -5 -7;1 -8 -9 10 8;-11 10 -8
3 8;-11 -8 4 2 -4] find matrices P, L, and U so that PA = LU using
Matlab's lu function. Based on your results: did Matlab use
pivoting during the lu-computation?
b) For b = [4;-4;-5;3;7] solve Ax =...
For the system
2x1 − 4x2 + x3 + x4 = 0,
x1 − 2x2 + 5x4 = 0,
find some vectors v1, . . . , vk such that the solution set to
this system equals span(v1, . . . , vk).
Solve the following systems of equation using the formula by
Cramer and with the inverse matrices.
4x1 - x2 + 2x3 = 8
-x1 + 2x2 = -7
x1 - 3x2 - 5x3 = 2
Use LU decomposition to solve the following system of equations
(show your work). Do not use a pivoting strategy, and check your
results by using the matrix inverse to show that [A][A]-1= [I].
8x+ 2y−z=10
- 2x+4y+z=5
3x−y+ 6z=7
(a) The curve with equation y2 =
x3 + 3x2 is called the
Tschirnhausen cubic. Find an equation of the
tangent line to this curve at the point
(1, 2).
y =
(b) At what points does this curve have horizontal tangents?
(x, y)
=
(smaller y-value)
(x, y)
=
(larger y-value)
(c) Illustrate parts (a) and (b) by graphing the curve and the
tangent lines on a common screen.