JEE Main201910 Apr 2019Evening ShiftMathematicsQuadratic EquationActual
The number of real roots of the equation 5 + 2 x - 1 = 2 x 2 x - 2 is :
Options
- A2
- B3
- C1
- D4
Correct answer
C. 1
Step-by-step solution
Let 2 x = t 5 + t - 1 = t 2 - 2 t ⇒ t - 1 g t = t 2 - 2 t - 5 f t Since, 2 x > 0   ∀ x ∈ R ⇒ t > 0 From the graph, we have It is clear from the graph that the two graphs have only one point of intersection. So, number of real roots of the given equation is 1 .