The problem statement gives the correct answers for parts (a) and (b). The total number of roots of the characteristic polynomial is the dimension of the matrix: 6. The eigenvalues are the zeros of the characteristic polynomial, 3 (multiplicity 2), 6 (multiplicity 3), and -1.
(c) The matrix is not invertible when one or more eigenvalues is zero. None of yours are zero, so the matrix is invertible.
Answer:
LM = 85.5
Step-by-step explanation:
B1 + B2/2
46 + 125/2
LM = 85.5
The expression is

.
Collecting the constants, the first degree, and second degree terms together we have:

.
Answer: 0
Step-by-step explanation:
or,[(√-x-1)+(√x+9)]^2=4^2
or,(√-x-1)^2+2√(-x-1)(x+9)+(√x+9)^2=16
or,-x-1+2√-x^2-10x-9 +x+9=16
or,2√-x^2-10x-9=8
or,√-x^2-10x-9=4
squaring on both sides
or,-x^2-10x-9=16
or,-x^2-10x=25
or,-x(x+10)=25
Either,
x=-25 or, x=15.
Answer:
x ≥ 7
Step-by-step explanation:
|x - 7| = x - 7
A. For each absolute, find the intervals
x - 7 ≥ 0 x - 7 < 0
x ≥ 7 x < 7
If x ≥ 7, |x - 7| = x - 7 > 0.
If x < 7, |x - 7| = x - 7 < 0. No solution.
B. Solve for x < 7
Rewrite |x - 7| = x - 7 as
+(x - 7) = x - 7
x - 7 = x - 7
-x + 14 = x
14 = 2x
x = 7
7 ≮7. No solution
C. Solve for x ≥ 7
Rewrite |x - 7| = x - 7 as
+(x - 7) = x - 7
x - 7 = x - 7
True for all x.
D. Merge overlapping intervals
No solution or x ≥ 7
⇒ x ≥ 7
The diagram below shows that the graphs of y = |x - 7| (blue) and of y = x - 7 (dashed red) coincide only when x ≥ 7.