Respuesta :

Answer:

[tex](\frac{dy}{dx})x_{= \frac{\pi }{2} } = f^{1} (\frac{\pi }{2} ) =2[/tex]

Step-by-step explanation:

Step(i):-

Given that

 [tex]f(x) = \frac{5x}{sinx} -3xsinx[/tex]

Apply (UV )¹ = UV¹+VU¹

[tex]\frac{d}{dx} (\frac{U}{V} ) = \frac{V U^{l} -VU^{l} }{V^{2} }[/tex]

Step(ii):-

[tex]f^{1} (x) = 5\frac{sin x(1)-x(cos x)}{sin^{2}x } - 3(x cos x + sin x(1))[/tex]

put  [tex]x = \frac{\pi }{2}[/tex]

[tex]f^{1} (\frac{\pi }{2} ) = 5\frac{sin \frac{\pi }{2} (1)-\frac{\pi }{2} (cos \frac{\pi }{2} )}{sin^{2}(\frac{\pi }{2} ) } - 3(\frac{\pi }{2} cos \frac{\pi }{2} + sin(\frac{\pi }{2}) (1))[/tex]

we know that  

[tex]cos(\frac{\pi }{2}) = 0[/tex]  

[tex]sin(\frac{\pi }{2} ) = 1[/tex]

[tex]f^{l} (\frac{\pi }{2} ) = \frac{5(1-0)}{1} -3(0+1)[/tex]

[tex]f^{1} (\frac{\pi }{2} ) = 5-3 =2[/tex]

Final answer:-

[tex](\frac{dy}{dx})x_{= \frac{\pi }{2} } = f^{1} (\frac{\pi }{2} ) =2[/tex]