(Solved): Find tue value of \( d^{2} y / d x^{2} \) at tee point defined by tue given value 7 \( t \). \( x=\ ...

Find tue value of \( d^{2} y / d x^{2} \) at tee point defined by tue given value 7 \( t \). \( x=\tan t, y=9 \sec t, \quad t=\frac{3 \pi}{4} \) (a) \( \frac{\sqrt{2}}{4} \) (b) \( \frac{9 \sqrt{2}}{4} \) (c) \( 9 \sqrt{2} \) (d) \( -\frac{9}{2} \)