Question 1119443: Find the slope of the line through the points P and Q when:
a. P(1,3) and Q(x, x2+3x-1)
b. P(x, x2+3x-1) and Q(x+h, (x+h)2+3(x+h)-1)
Answer: (Write the variables or letters first, then the number, say x+h+1)
a. m= _____
b. m= _____
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! m is change in y/change in x and is (x^2+3x-4)/(x-1)
This is (x+4)(x-1)/(x-1) or x+4 so long as x does not equal 1.
Change in y is x^2+2xh+h^2+3x+3h-1-x2-3x+1, and that is divided by h to give (2xh+h^2+3h)/h
Factor out an h and divide top and bottom by them to get 2x+h+3
(and as h gets smaller and smaller, the limit will be 2x+3, which is called the derivative).
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