JEE Advanced | 2013Quadratic EquationHard
Question
The number of points in (- ∞,∞), for which x2 - xsinx - cosx = 0, is
Options
A.6
B.4
C.2
D.0
Solution
f(x) = x2 - xsinx - cosx
f′(x) = 2x - xcosx - sinx + sinx = x (2 - cosx)

∴ graph of f(x) will be

∴ f(x) is zero for 2 values of x
∴ (c)
Create a free account to view solution
View Solution FreeMore Quadratic Equation Questions
If roots of the equation x2 - bx + c = 0 be two consectutive integers, then b2 - 4c equals...Suppose 1, 2, 3 are the roots of the equation $x^{4} + ax^{2} + bx = c$. Then the value of $c$ is...The roots of a1 x2 + b1 x + c1 = 0 are reciprocal of the roots of the equation a2x2 + b2x + c2 = 0, if-...For what value of a the sum of roots of the eqn. x2 + 2 (2 − a − a2)x − a2 = 0 is zero -...The expression y = ax2 + bx + c has always the same sign as c if -...