Question 1044841: please help me solve this equation. Find f(x + h) when f(x) = -3x+5 over 7x+4 Found 2 solutions by MathLover1, Boreal:Answer by MathLover1(20850) (Show Source):
You can put this solution on YOUR website! f(x+h)=-3(x+h)+5/7(x+h)+4
That is -3x-3h+5/(7x+7h+4)
If they want f(x+h)-f(x)
-3x-3h+5/(7x+7h+4)-(-3x+5)/(7x+4); common denominator is (7x+7h+4)(7x+4)
The numerator is (-3x-3h+5)(7x+4)-(-3x+5)(7x+7h+4)
=-21x^2-12x-21xh-12h+35x+20-(-21x^2-21xh-12x+35x+35h+20)
=-21x^2-12x-21xh-12h+35x+20+21x^2+21xh+12x-35x-35h-20
=-47/[7(x+h)+4](7x+4)
=-47/(7x+4)^2 as h approaches 0. This is the derivative.
