esin⁡ x−e−sin⁡ x=4 for

esin⁡x=4+1esin⁡x−1≤sin⁡x≤1 and e>1e−1≤esin⁡x≤e<3.⇒esin⁡x<3, also esin⁡x>0.∴1esin⁡x+4>4.So two sides of (1) cannot be equal for any real value of x.