Q. For the function f(x)=−x2+4x−8, find the slope of the secant line between x=2 and x=5.Answer:
Define Slope Formula: To find the slope of the secant line between two points on a function, we use the formula for slope, which is the change in y divided by the change in x, or x2−x1f(x2)−f(x1). Here, x1=2 and x2=5.
Find f(2): First, we need to find the value of the function at x=2. We substitute x=2 into the function f(x)=−x2+4x−8 to get f(2)=−(2)2+4(2)−8.
Calculate f(2): Calculating f(2) gives us f(2)=−4+8−8=−4.
Find f(5): Next, we need to find the value of the function at x=5. We substitute x=5 into the function f(x)=−x2+4x−8 to get f(5)=−(5)2+4(5)−8.
Calculate f(5): Calculating f(5) gives us f(5)=−25+20−8=−13.
Calculate Slope: Now we have the function values at both points: f(2)=−4 and f(5)=−13. We can use these to find the slope of the secant line: slope=5−2f(5)−f(2).
Substitute Values: Substituting the values we found, the slope is (−13−(−4))/(5−2)=(−13+4)/3=−9/3.
Final Slope Calculation: Calculating the slope gives us −9/3=−3.
More problems from Find the roots of factored polynomials