Problem i 33%" It is mentioned in Chapter 7 of ISL that a cubic regression spline with one knot at &can be obtained using a basis of the form z, r2,T3, [r- ] , where Iz-d-(z-E)3 if z > and equals 0 otherwise. We will now show that a function of the form is indeed a cubic regression spline, regardless of the values of ??-??2?,?4. 1. Find a cubic polynomial such that f(z)-fi (z) for all z 2. Find a cubic polynomial ?. Express aib,,ci,di ?n terms of%,AAnAsA. such that f(x)-fa(z) for all ! > . Express a2.h,c2-d2 in terms of A-A.h.h'?, we have now established that f(x) is a piecewise polynomial 3. Show that fi (E)-fg(E). That is, f(x) is continuous at ?. Problem i 33%" It is mentioned in Chapter 7 of ISL that a cubic regression spline with one knot at &can be obtained using a basis of the form z, r2,T3, [r- ] , where Iz-d-(z-E)3 if z > and equals 0 otherwise. We will now show that a function of the form is indeed a cubic regression spline, regardless of the values of ??-??2?,?4. 1. Find a cubic polynomial such that f(z)-fi (z) for all z 2. Find a cubic polynomial ?. Express aib,,ci,di ?n terms of%,AAnAsA. such that f(x)-fa(z) for all ! > . Express a2.h,c2-d2 in terms of A-A.h.h'?, we have now established that f(x) is a piecewise polynomial 3. Show that fi (E)-fg(E). That is, f(x) is continuous at