(x) = arcsec(x) − 8x
f'(x) = d/dx( arcsec(x) −
8x )
<span> 1/xsqrt( x^2 - 1) - 8</span>
f'(x) = 0
1/xsqrt( x^2 - 1) - 8 = 0
8 x sqrt (x^2-1) = 1
<span> ( 8 x sqrt (x^2-1) )^2 = 1</span>
64 x^2 ( x^2 - 1) = 1
64 x^4 - 64 x^2 =1
64 x^4 - 64 x^2 - 1 = 0
x = 1.00766 , - 1.00766
<span> x = - 1.00766</span>
f(- 1.00766) = arcsec(-
1.00766) − 8( - 1.00766)
f( - 1.00766 ) = 11.07949
x = 1.00766
f(1.00766) =
arcsec(1.00766) − 8( 1.00766)
f(1.00766 ) = -7.93790
relative maximum (x, y) =
(- 1.00766 , 11.07949 ) relative minimum (x, y) = ( 1.00766 ,
-7.93790 )
If I’m correct is rational
