CAT 2019 Question Paper | Quants Slot 1

CAT 2019 did not have a lot of classic mensuration questions that we have seen in CAT previous year papers. However this question was a direct application of the mensuration formulas. Anybody who has done a good CAT Preparation would have been able to tackle this question easily. It deals with the basics of diagnols and sides of quadrilaterals.

Question 29 : The number of solutions of the equation |x|(6x² + 1) = 5x² is [TITA]

Video Explanation

Explanatory Answer

|x| (6x² + 1) = 5x²
We know that |x²| = x²
Let y = |x|
So, y² = x²
So, y (6y² + 1) = 5y²
6y² + 1 = 5y
6y² -5 + 1 = 0
y = or
Since, y = |x|
y = or , or
Since we have cancelled y in our first step, x = 0 is also a solution
So, Number of possible solutions = 4 + 1 = 5

The question is "The number of solutions of the equation |x|(6x² + 1) = 5x² is [TITA] "

Hence, the answer is 5