Questions: HW16 Rational Functions: Problem 2
(5 points) Suppose (f(x)=frac2 x^2-4x^3-6).
1. Evaluate (f(5)= (46) /(119))
2. What are the (x)-intercept of (f(x)) ? Write your answer as an ordered pair.
(sqrt(2),0),(-sqrt(2),0)
3. What is the (y)-intercept of (f(x)) ? Write your answer as an ordered pair.
((0,(2) /(3)))
4. Write the equation of the vertical asymptote of (f(x)) :
5. Write the equation of the horizontal asymptote of (f(x)) :
Transcript text: HW16 Rational Functions: Problem 2
(5 points) Suppose $f(x)=\frac{2 x^{2}-4}{x^{3}-6}$.
1. Evaluate $f(5)=$ $(46) /(119)$
2. What are the $x$-intercept of $f(x)$ ? Write your answer as an ordered pair.
(sqrt(2),0),(-sqrt(2),0)
3. What is the $y$-intercept of $f(x)$ ? Write your answer as an ordered pair.
\[
(0,(2) /(3))
\]
4. Write the equation of the vertical asymptote of $f(x)$ :
5. Write the equation of the horizontal asymptote of $f(x)$ :
Solution
Solution Steps
Solution Approach
To evaluate f(5), substitute x=5 into the function f(x)=x3−62x2−4 and simplify the expression.
To find the x-intercepts, set the numerator of the function equal to zero and solve for x. The x-intercepts occur where the function equals zero, i.e., where 2x2−4=0.
To find the y-intercept, evaluate the function at x=0. This is done by substituting x=0 into the function and simplifying.
Step 1: Evaluate f(5)
To evaluate f(5), we substitute x=5 into the function:
f(5)=(5)3−62(5)2−4=125−650−4=11946
Step 2: Find the x-intercepts
The x-intercepts occur where the function equals zero, which is when the numerator is zero:
2x2−4=0⟹x2=2⟹x=±2
Thus, the x-intercepts are (−2,0) and (2,0).
Step 3: Find the y-intercept
To find the y-intercept, we evaluate the function at x=0:
f(0)=(0)3−62(0)2−4=−6−4=32
Thus, the y-intercept is (0,32).