SOLUTION: a) Solve the simultaneous equation : 𝑦 = 𝑥^2 − 3𝑥+2 and 𝑦 = 3𝑥−7 b) Interpret your solution to part (i) geometrically

Algebra ->  Test -> SOLUTION: a) Solve the simultaneous equation : 𝑦 = 𝑥^2 − 3𝑥+2 and 𝑦 = 3𝑥−7 b) Interpret your solution to part (i) geometrically      Log On


   



Question 1200163: a) Solve the simultaneous equation : 𝑦 = 𝑥^2 − 3𝑥+2 and 𝑦 = 3𝑥−7
b) Interpret your solution to part (i) geometrically

Answer by ikleyn(52885) About Me  (Show Source):
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Solve the simultaneous equation : 𝑦 = 𝑥^2 − 3𝑥+2 and 𝑦 = 3𝑥−7
b) Interpret your solution to part (i) geometrically.
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y = x^2 − 3x + 2  represents a parabola.

y = 3x - 7        represents a straight line.


Simultaneous solution represents the intersection points.


From  y = x^2 − 3x + 2  and  y = 3x - 7  we get, by substitution

    x^2 - 3x + 2 = 3x - 7.


Collecting the terms on the left side, we transform it to the standard form quadratic equation

    x^2 - 6x + 9 = 0.


Left side is a full square

    (x-3)^2 = 0.


So, x= 3 is the solution to the quadratic equation of multiplicity 2.

In other words, two solutions of the quadratic equation do merge in one single point.

Geometrically, it means  that the straight line  y = 3x-7  is a tangent to the parabola.


The tangent point is x= 3,  y= 3x-7 = 3*3-7 = 2.

Solved, with complete explanations.