5. Use Newton's method to find solutions accurate to within \( 10^{-4} \) for the following problems.
a. \( x^{3}-2 x^{2}-5=0 \),
\( [1,4] \)
c. \( x-\cos x=0 \),
\( [0, \pi / 2] \)
b. \( x^{3}+3 x^{2}-1=0, \quad[-3,-2] \)
d. \( \quad x-0.8-0.2 \sin x=0, \quad[0, \pi / 2] \)