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)
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