Let f(x) = x^3 - 10x. Calculate the difference quotient f(2 + h) - f(2) / h for specific values of h (h = 0.1, 0.01, -0.01, -0.1).
Solution
Let’s analyze the problem in the uploaded image.
The problem involves calculating the difference quotient for the given function f(x)=x3−10x. The difference quotient formula is:
hf(2+h)−f(2)
You are provided specific values of h (e.g., h=0.1,0.01,−0.01,−0.1) and need to calculate the difference quotient for each case.
Steps to Solve:
Find f(2):
Substitute x=2 into f(x)=x3−10x:
f(2)=23−10(2)=8−20=−12.
Find f(2+h):
Substitute x=2+h into f(x)=x3−10x:
f(2+h)=(2+h)3−10(2+h).
Expand (2+h)3=8+12h+6h2+h3:
f(2+h)=8+12h+6h2+h3−20−10h=−12+2h+6h2+h3.
Calculate the difference quotient:
Substitute f(2+h) and f(2) into the formula:
hf(2+h)−f(2)=h−12+2h+6h2+h3−(−12).
Simplify the numerator:
h−12+2h+6h2+h3+12=h2h+6h2+h3.
Factor h out of the numerator:
hh(2+6h+h2)=2+6h+h2.
Evaluate for each h:
Substitute the given values of h:
For h=0.1: 2+6(0.1)+(0.1)2=2+0.6+0.01=2.61.
For h=0.01: 2+6(0.01)+(0.01)2=2+0.06+0.0001=2.0601.
For h=−0.01: 2+6(−0.01)+(−0.01)2=2−0.06+0.0001=1.9401.
For h=−0.1: 2+6(−0.1)+(−0.1)2=2−0.6+0.01=1.41.
Final Results:
For h=0.1: 2.61
For h=0.01: 2.0601
For h=−0.01: 1.9401
For h=−0.1: 1.41
Let me know if you’d like further clarification!
Related Questions:
What happens to the difference quotient as h→0?
How does the difference quotient relate to the derivative of a function?
Can this process be generalized for any polynomial f(x)?
How would the result change if f(x) had an additional constant term?
Why is expanding (2+h)3 important in this problem?
Tip:
Always double-check your algebraic expansions and substitutions when working with polynomials to avoid small errors that propagate through the calculations!