P P-isabel New member Joined May 17, 2019 Messages 3 May 27, 2019 #1 I need help to find dy/dx of the two following: x(t)=3cos(4t) y(t)=5sin(3t) I know that: x(t)=3 cos(4t) d/dt= -12sin(4t) and y(t)=5sin(3t) d/dt =15cos(3t)

I need help to find dy/dx of the two following: x(t)=3cos(4t) y(t)=5sin(3t) I know that: x(t)=3 cos(4t) d/dt= -12sin(4t) and y(t)=5sin(3t) d/dt =15cos(3t)

Dr.Peterson Elite Member Joined Nov 12, 2017 Messages 3,847 May 27, 2019 #2 Do you know that dy/dx = (dy/dt)/(dx/dt)? This is a version of the chain rule.

P P-isabel New member Joined May 17, 2019 Messages 3 May 27, 2019 #3 Dr.Peterson said: Do you know that dy/dx = (dy/dt)/(dx/dt)? This is a version of the chain rule. Click to expand... So that means its--> 15cos(3t)/-12sin(4t)

Dr.Peterson said: Do you know that dy/dx = (dy/dt)/(dx/dt)? This is a version of the chain rule. Click to expand... So that means its--> 15cos(3t)/-12sin(4t)

Dr.Peterson Elite Member Joined Nov 12, 2017 Messages 3,847 May 27, 2019 #4 P-isabel said: So that means its--> 15cos(3t)/-12sin(4t) Click to expand... Yes, but write that more carefully, with parentheses, (15cos(3t))/(-12sin(4t)), and simplify it a bit (canceling a common factor). There's not much more you can do.

P-isabel said: So that means its--> 15cos(3t)/-12sin(4t) Click to expand... Yes, but write that more carefully, with parentheses, (15cos(3t))/(-12sin(4t)), and simplify it a bit (canceling a common factor). There's not much more you can do.