Number of real roots of the equation e^{sin x} –e^-sin x -4 = 0 is

^{esin x.esin x-4esin x-1=0}

e^{sin x=(4+2 )/2 , (4-2 )/2}

^=2+ ,2-

^{approve if u like....}

ans: zero

on solvin tha quadratic in e^(sinx) we obtain values 2+√5 and 2-√5 => sinx = ln(2+√5)/ln(2-√5)

ln(2+√5) > 1 and ln(2-√5)- is nt defined

hence der is no real root  for given equation.....