Find the derivative f(x)=5x at x=3?

3 ⤊

Find the derivative f(x)=5x at x=3?

The answer if 5...but how?

2007-10-23 08:26:49 · 3 answers · asked by Caramel 2 in Science & Mathematics ➔ Mathematics

3 answers

The function has a graph which is a straight line with slope 5.

the derivative at x=3 is the slope of the line which is "tangent" to the graph of the function at x=3. But a straight line IS it's own tangent line. The slope is 5 at every value of x, so the derivative is 5 at every value of x.

2007-10-23 08:33:03 · answer #1 · answered by Michael M 7 · 1⤊ 0⤋

f `(x) = 5 for all x
So f `(3) = 5

2007-10-23 17:52:23 · answer #2 · answered by Como 7 · 1⤊ 0⤋

d/dx(5x) is always 5

No matter where x is on the axis

2007-10-23 15:33:42 · answer #3 · answered by TomandJerry 2 · 1⤊ 0⤋