Holooly Plus Logo

Question 8.3.9: Graph the inequality 27y³ ≤ 8+x³....

Graph the inequality 27y³ ≤ 8+x³.

Question Data is a breakdown of the data given in the question above.

Inequality: 27y³ ≤ 8+x³.

The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.
Step 1:
To solve the equation for y, we start by isolating y on one side of the equation. We have 27y^3 = 8 + x^3. To isolate y, we divide both sides of the equation by 27, giving us y^3 = (8 + x^3)/27.
Step 2:
Next, we want to solve for y, so we take the cube root of both sides of the equation. This gives us y = (1/3) * ∛(8 + x^3).
Step 3:
To visualize the solution, we can assign the expression (1/3) * ∛(8 + x^3) to Y1 and graph it in the viewing rectangle [-6, 6] by [-4, 4]. This will give us a graph that represents the solution to the equation.
Step 4:
To shade the region below the graph of Y1, we can use the Shade command on a TI-83/4 Plus calculator. The parameters for the Shade command are as follows: -4 is the lower function for the shaded region (in this case, we use the value of Ymin). Y1 is the upper function for the shaded region. -6 and 6 are Xmin and Xmax. 1 is the shading pattern, and 3 shades every third pixel.
Step 5:
Pressing ENTER will give us the graph with the shaded region below the graph of Y1.
Step 6:
Alternatively, we can use the graphing styles on the Y= screen to select the "shade below" style. This can be done by moving the cursor to the left of Y1 and pressing ENTER to cycle through the graphing styles. Selecting the "shade below" style and pressing GRAPH will produce the same shaded figure as before.

Final Answer

We must first solve the associated equality for y:

\begin{aligned}27 y^3 & =8+x^3 & & \text { equality } \\y^3 & =\frac{1}{27}\left(8+x^3\right) & & \text { divide by } 27 \\y & =\frac{1}{3} \sqrt[3]{8+x^3} & & \text { take the cube root of both sides }\end{aligned}

We assign \frac{1}{3} \sqrt[3]{8+x^3}  \text {to}  Y_1  \text {and graph}  Y_1 in the viewing rectangle [-6, 6] by  [-4, 4] , as shown in Figure 12. The test point  (0, 0)  is in the solution region (since  0 ≤ 8  is true), so we want to shade the region below the graph of Y_1. The commands for the TI-83/4 Plus are shown.

\begin{aligned}& \boxed {\text {2nd}}\quad \boxed {\text {DRAW}}\quad \boxed {7}\quad -4 \quad \boxed {,} \quad \boxed {\text {VARS}}\\&\boxed {\vartriangleright}\quad \boxed {1}\quad \boxed {1}\quad \boxed {,} \quad -6 \quad \boxed {,} \quad 6 \quad \boxed {,}\\&1\quad \boxed {,}\quad 3 \quad \boxed {)}\end{aligned}

The parameters for the Shade command are as follows:

-4 is the lower function for the shaded region – in this case, we simply use the value of Ymin. Y_1 is the upper function for the shaded region.
-6 and 6 are Xmin and Xmax.
1 is the shading pattern; there are four of them.
3 shades every third pixel; you may specify an integer from 1 to 8 .

Pressing \boxed {\text {ENTER}} gives the following graph.

Alternative Method: There is an alternative method for shading available. It can be executed by selecting a graphing style from the \boxed {Y=} screen.

Using the cursor keys, move the cursor to the left of ” Y_1.” Successively press \boxed {\text {ENTER}} to cycle through the seven graphing styles. Select the “shade below” style as shown in the figure. Pressing \boxed {\text {GRAPH}} produces a shaded figure as before.

figure 12
1
2
Loading more images...

Related Answered Questions

Question: 8.5.2

Verified Answer:

We begin with the matrix of the system—that is, wi...
Question: 8.9.4

Verified Answer:

The determinant of the coefficient matrix is [late...
Question: 8.9.5

Verified Answer:

We shall merely list the various determinants. You...
Question: 8.3.3

Verified Answer:

We replace each ≤ with = and then sketch the resul...
Question: 8.3.4

Verified Answer:

The first two inequalities are the same as those c...
Question: 8.3.5

Verified Answer:

Using properties of absolute values (listed on pag...
Question: 8.3.6

Verified Answer:

The graphs of x²+y²=16 and x+y=2 are the circle an...
Question: 8.3.7

Verified Answer:

An equation of the circle is x²+y²=5². Since the i...
Question: 8.9.1

Verified Answer:

We plan to use property 3 of the theorem on row an...
Question: 8.9.3

Verified Answer:

\left|\begin{array}{ccc}1 & 1 & 1 \...