I need help finding the difference quotient for the following function.
f(x)=5x-4
Find for these:
1) f(x+h)=
2) f(x)=
3)f(x+h)-f(x)=
4)(f(x+h)-f(x))/h=
It's just a matter of substituting what's in the parentheses
just after the function letter "f", in place of x in the original
equation.
f(x)=5x-4
To find f(x+h) do this:
1. Write f(x)=5x-4 all spread out like this:
f( x ) = 5x - 4
1. Take out all x's, leaving big spaces when you took
them out, like this:
f( ) = 5 - 4
Now in those blank spaces where you took out the x's,
put in (x+h) and you have this
f(x+h) = 5(x+h)- 4
1) f(x+h) = 5x+5h-4 <--simplified answer to 1)
2) f(x) = 5x-4 <--answer to 2), that's given
f(x+h)-f(x) = (5x+5h-4) - (5x-4) <--be sure to use () here
f(x+h)-f(x) = 5x+5h-4-5x+4
3) f(x+h)-f(x) = 5h <--simplified answer to 3)
[f(x+h)-f(x)]/h = (5h)/h
4) [f(x+h)-f(x)]/h = 5 <-- simplified answer to 4), which is
just the number 5.
Edwin