11 - Equations and Inequalities Questions Answers
The maximum number of real roots of the equation 2x88 + 3x87 − 13x2 + 5x + 9 = 0 is
Asked By: HIMANSHU MITTAL
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Joshi sir comment
2x88 + 3x87 − 13x2 + 5x + 9 = 0
implies that 2x88 + 3x87 = 13x2 - 5x - 9
or x87(2x+3) = 13x2 - 5x - 9
now plot the left and right graphs for getting the intersecting points
Hint: Parabola will face in upward direction as a is positive, take x=0 we get -9 so 1 root will be positive and 1 negative,
x87(2x+3) will be 0 for x = -3/2 and x = 0 besides it consider some values as x = 1 and -1
You will get one root between 0 and -1
now check both the graph at x= -2, you will get the idea about the second intersection