 |
| ||
| |||
|
| Math Central | Quandaries & Queries |
|
Question from Marie, a student: For each function defined as follows, find a.) f (x+h) b. f(x+h)-f(x) c. [f(x+h)- f(x)]/h. Problem: f(x)= -1/ x^2. Help me solve part b and c |
Marie,
Try some numbers first.
- If x = 3 then f(x) = f(3) = -1/32 = -1/9.
- If x = 3 + 5 then f(x) = f(3 + 5) = -1/(3 + 5)2 = -1/82 = -1/64.
- If x = 3 + h then f(x) = f(3 + h) = -1/(3 + h)2.
I hope now you see that f(x + h) = -1/(x + h)2.
Thus for b, 
. Write the two fractions with a common denominator and then simplify the numerator.
Write back and tell me what you got,
Harley
| ||
| ||
| ||
 |
 |
|
Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.