I need to know how to solve the equation graphically.
See image below
Solving the Equation Graphically
Using the graphing calculator, put in the formula. When the function touches or goes through the x-axis are the solutions to this equation.
Solving the Equation
I don't know how to solve a cubic, so I use the factor theorem. If I use a positive number, I get a negative answer. So I try a negative numbers, starting with -1. Using -1, the result is 0, so (x-(-1)) or (x+1) is a factor. Knowing (x+1) is a factor, we can divide it into the equation using long division. When I do this, I get 2x^2-6x+1 as a quotient. I couldn't factor this over integers, so I used the quadratic formula to get the roots of (3+/-root(7))/2.
Graphing
Now we have the 3 zeros of the equation, we can sketch the function. Now we need to know what the function does at the extremes. If we put a large negative number in for x, y will be a larger negative number. Similarly, if we put a large x value, we will get a larger positive number.
Good luck,
Paul
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