1 Answers
Lokesh Verma
·2009-03-30 06:58:16
sin x / x < sin (sin x) / sin x
we just have to prove that sin x / x is a
f(x) = sin x / x
just proving that f(x) is decreasing in interval (0,1) will prove this !!!
cos x / x - sin x / x2 = (x cos x - sin x)/x2
so prve that x cos x - sin x < 0 for 0 < x <1
which is true because
derivative of this is - x sin x <0 for 0<x<1
hence the above is proved