[tex](a)\\\\\text{Given that, sin x = cos x }\\\\\text{So,} ~ \tan x = \dfrac{\sin x}{\cos x} = \dfrac{\sin x}{\sin x} = 1\\\\\\(b)\\\\\text{Given that,}\\\\\sin x = \cos x\\\\\implies \dfrac{\sin x}{\cos x} =1\\\\\implies \tan x =1\\\\\implies x = n\pi + \dfrac{\pi} 4 \\\\\text{For interval}~ [0, 2\pi),}\\\\x= \dfrac{\pi}4, \dfrac{5\pi}4~~;[\text{When n = 0,1}]\\\\\text{In degrees,} ~ x= 45^{\circ} , 225^{\circ}[/tex]
