# Homework # 4 (The Chain Rule) # OPMT 5701 # Fall 2006 # # Problem 1: > y:=1/(2-3*x)^4; > y_prime:=diff(y,x); # # # Problem 2: > y:=1/(4*x^2-3)^(1/3); > y_prime:=diff(y,x); # # Problem 3: > y:=sqrt(sqrt(x+1)); > y_prime:=diff(y,x); # # Problem 4: > y:=x^2*(2*x-5)^5; > y_prime:=diff(y,x); > factor(%); # # # Problem 5: > y:=(x^2+9)*sqrt(x^2+4); > y_prime:=diff(y,x); > simplify(%); # # Problem 6: > y:=((x+2)/(x-3))^4; > y_prime:=diff(y,x); > simplify(%); # # Problem 7: > f:=(x+1)^2*(x+2)^3; > f_prime:=diff(f,x); > factor(%); # # # Multiple Choice: # # Problem 8: > y:=sqrt(x^2-9); > yprime:=diff(y,x); > slope:=subs(x=5,yprime); > simplify(slope); # So, we know that the slope of the tangent line is: 5/4. Let us now plug in a point on the line: # > y0:=subs(x=5,y); # > y_tangent:=slope*(x-5)+y0; > simplify(%); # as we can tell from the above equation for the line, the answer is E) y = 5*(`*`(x))/(`*`(4))+`-`(`*`(9)/(`*`(4)));. # # Problem 9: > g:=x^4*(2*x-1)^10; > g_prime:=diff(g,x); > slope:=subs(x=1,g_prime); # so, the answer is B) 24. # # Problem 10: > y:=u^5-8*u^2+2*u-1; > u:=sqrt(x+10); > y_prime:=diff(y,x); > slope:=subs(x=-9,y_prime); # so, the answer is B) `+`(`-`(`*`(9)/(`*`(2))));. > #