A. Evaluate the polynomial y = x3− 5x2 + 6x + 0.55 at x = 1.37.

Use 3-digit arithmetic with chopping. Evaluate the percent relative round-off error.

b. Express y as y = ((x − 5)x + 6)x + 0.55 (this is the same equation). Use again 3-digit arithmetic with chopping. Evaluate the percent relative round-off error and compare with part (a). Make the conclusion about which form of the polynomial is superior.

a) y = x³− 5x² + 6x + 0.55 at x = 1.37.

Use 3-digit arithmetic with chopping. Evaluate the percent relative round-off error.

-1.183%

b. Express y as y = ((x − 5)x + 6)x + 0.55 (this is the same equation). Use again 3-digit arithmetic with chopping. Evaluate the percent relative round-off error and compare with part (a). Make the conclusion about which form of the polynomial is superior.

-0.161%

Comparing part a and b together, part b is more superior because the percent(%) error is smaller when compared to part a

Step-by-step explanation:

a) y = x³− 5x² + 6x + 0.55 at x = 1.37.

Use 3-digit arithmetic with chopping. Evaluate the percent relative round-off error.

Let's evaluate before applying the 3 digit arithmetic chopping rule

y = 1.37³ - 5 × 1.37² + 6 × 1.37 + 0.55

y = 1.956853

Let evaluate each components of the polynomial one by one

Note that: 3-digit arithmetic chopping means to approximate chop off or remove number after the 3 significant figures.

y = x³− 5x² + 6x + 0.55 at x = 1.37.

x³ = 1.37³ = 2.571353

≈ 2.57

x² = 1.37² = 1.8769

≈ 1.88

5x² = 1.87 × 5

= 9.35

x = 1.37

6x = 1.37 × 6

6x = 8.22

Evaluating the polynomial

y = 2.57 - 9.38 + 8.22 + 0.55

y = 1.98

The percent relative round-off error =

1.956853 - 1.98/1.956853 × 100

= -1.183%

b. Express y as y = ((x − 5)x + 6)x + 0.55 (this is the same equation). Use again 3-digit arithmetic with chopping. Evaluate the percent relative round-off error and compare with part (a). Make the conclusion about which form of the polynomial is superior.

y = ((x − 5)x + 6)x + 0.55

Evaluating with the 3 digit chop off rule is applied

= ((1.37 - 5)1.37 + 6)1.37 + 0.55

=( 1.8769 - 6.85) + 6) 1.37 + 0.55

= (- 4.9731 + 6 )1.37 + 0.55

= 1.0269 × 1.37 + 0.55

= 1.406853

= 1.956853.

≈ 1.96

Note in: evaluating before applying the 3 digit arithmetic chopping rule

y = 1.37³ - 5 × 1.37² + 6 × 1.37 + 0.55

y = 1.956853

The percent relative round-off error

1.956853 - 1.96/1.956853 × 100

= -0.161%

Comparing part a and b together, part b is more superior because the percent(%) error is smaller when compared to part a

hello from mrbilldoesmath!

answer:   x (x+6)^2, choice b

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb