equation of the secant line - urgent help please!

Question

Let f(x)=5.9x^2 − 2.6x.

Can someone help me find the equation of the secant line on the graph of f(x) between x1 = 2 and x2 = 7

 ---- with the answer in mx + b format?

Answer 1

The secant line is the line connecting the two points. Given the x coordinates, you can determine the y coordinates by plugging x's into the original equation. That is, at x=2, y = 18.4. Similarly, when x = 7, y = 270.9. Therefore the rise between these two points is 252.5, whereas the fun is 5 making the slope 252.5/5. You know have a slope (m) and you have a point (select either (2,18.4) or (7,252.5)). Plug them into the equation y= mx+b and solve the the b. Then put the m and b and you have your equation.