QUESTION IMAGE
Question
- in a video game, the amount of damage a player’s character can do is calculated based function
$d(l) = \frac{10l^2}{l^2 + 6}$
(a) calculate $d(2)$. interpret your answer in the context of the problem using units and
(b) calculate (and interpret in context) the aroc of $d(l)$ on the interval $0, 2$.
(c) is $d(l)$ one-to-one? explain your answer.
(d) find $l$ such that $d(l) = 6$.
(e) state the end behavior of $d(l)$. explain what the end behavior means in the context
Part (a)
Step 1: Substitute \( L = 2 \) into \( D(L) \)
We have the function \( D(L)=\frac{10L^{2}}{L^{2}+6} \). Substitute \( L = 2 \) into the function:
\( D(2)=\frac{10\times(2)^{2}}{(2)^{2}+6} \)
Step 2: Simplify the expression
First, calculate the numerator and the denominator:
- Numerator: \( 10\times(2)^{2}=10\times4 = 40 \)
- Denominator: \( (2)^{2}+6=4 + 6=10 \)
Then, \( D(2)=\frac{40}{10}=4 \)
Interpretation: When the player's character has a level \( L = 2 \), the amount of damage the character can do is 4 (the unit of damage is not specified in the problem, but we can say that at level 2, the damage output is 4 units of damage).
Step 1: Recall the formula for AROC
The Average Rate of Change (AROC) of a function \( f(x) \) on the interval \([a,b]\) is given by \( \frac{f(b)-f(a)}{b - a} \). For our function \( D(L) \) on the interval \([0,2]\), \( a = 0 \) and \( b=2 \).
First, find \( D(0) \) and \( D(2) \) (we already know \( D(2) = 4 \) from part (a)).
Calculate \( D(0) \): \( D(0)=\frac{10\times(0)^{2}}{(0)^{2}+6}=\frac{0}{6}=0 \)
Step 2: Calculate AROC
Using the AROC formula: \( \text{AROC}=\frac{D(2)-D(0)}{2-0}=\frac{4 - 0}{2}=2 \)
Interpretation: On the interval from level \( L = 0 \) to \( L=2 \), the average rate of change of the damage function is 2. This means that, on average, for each unit increase in the level of the character (from level 0 to level 2), the damage output of the character increases by 2 units of damage per level.
Step 1: Recall the definition of a one - to - one function
A function \( y = f(x) \) is one - to - one if for every \( y \) value in the range, there is exactly one \( x \) value in the domain such that \( f(x)=y \). A function is one - to - one if and only if it passes the horizontal line test, or if \( f(a)=f(b) \) implies \( a = b \) for all \( a,b \) in the domain.
Let's assume \( D(a)=D(b) \), so \( \frac{10a^{2}}{a^{2}+6}=\frac{10b^{2}}{b^{2}+6} \)
Step 2: Cross - multiply and simplify
Cross - multiply: \( 10a^{2}(b^{2}+6)=10b^{2}(a^{2}+6) \)
Expand both sides: \( 10a^{2}b^{2}+60a^{2}=10a^{2}b^{2}+60b^{2} \)
Subtract \( 10a^{2}b^{2} \) from both sides: \( 60a^{2}=60b^{2} \)
Divide both sides by 60: \( a^{2}=b^{2} \)
Take square roots: \( a=\pm b \)
Since \( L \) represents the level of a character, \( L\geq0 \) (level cannot be negative). So if \( a^{2}=b^{2} \) and \( a,b\geq0 \), then \( a = b \). Wait, but let's test with some values. Let's take \( L = 1 \) and \( L=- 1 \) (but \( L=-1 \) is not in the domain as level can't be negative). Wait, actually, for non - negative \( L \), let's see if we can find two different non - negative \( L \) values with the same \( D(L) \).
Suppose \( L_1 = \sqrt{3} \) and \( L_2=\sqrt{3} \) (same value). Wait, no, let's check the derivative (or analyze the function). The function \( D(L)=\frac{10L^{2}}{L^{2}+6}=10-\frac{60}{L^{2}+6} \). As \( L \) increases, \( D(L) \) increases (since the denominator \( L^{2}+6 \) increases, so \( \frac{60}{L^{2}+6} \) decreases, and \( 10-\frac{60}{L^{2}+6} \) increases). So the function is increasing for \( L\geq0 \) (since the domain of \( L \) for a character's level is non - negative). For an increasing function, if \( D(a)=D(b) \), then \( a = b \). So the function is one - to - one on its domain (\( L\geq0 \)).
Wait, but let's check with the equation \( D(a)=D(b) \) for non - negative \( a \) and \( b \). From \( \frac{10a^{2}}{a^{2}+6}=\frac{10b^{2}}{b^{2}+6} \), we get \( 10a^{2}(b^{2}+6)=10b^{2}(a^{2}+6) \), \( 10a^{2}b^{2}+60a^{2}=10a^{2}b^{2}+60b^{2} \), \( 60a^{2}=60b^{2} \), \( a^{2}=b^{2} \). Since \( a\geq0 \) and \( b\geq0 \), we have \( a = b \). So the function is one - to - one.
Snap & solve any problem in the app
Get step-by-step solutions on Sovi AI
Photo-based solutions with guided steps
Explore more problems and detailed explanations
\( D(2)=4 \)