- #1
physphys
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Homework Statement
1. For the curve y = x^2+ x, and the point P (1,2)
a) determine the slope of the secant mPQ if Q(2, 6)
b) what is the slope of the secant if Q is at the following values of x
1.5 1.1 1.01 1.001
c) Estimate the value of the tangent to the curve at P. Reason?
Homework Equations
Y'= f(x+h)-f(x)
------------
h
The Attempt at a Solution
If i plug in the numbers into the y' equation i would get
y' = (2+h)^2 + 2 + h - 6
---------------------
h
which is h^2 + 5
and then h-> 0 so h = 5
I'm not sure if that is right, because isn't slope Δy/Δx ? and doing that would give me 4.
and when I use the slope function 2x+1, at point 2, 2(2)+1 = 5.
So I'm very confused between the difference in finding out the tangent line or the secant line. If you can just show me how to find the secant line in a) i can figure out b) on my own. Thanks!