JohnLockwood
New member
- Joined
- Jul 18, 2022
- Messages
- 2
Hi,
I was working this Kahn Academy exercise while self-studying differential calculus and boiled my inability to get the right answer down to this piece of product rule (chain rule?) that I wasn't getting somehow:
[math]\frac{d}{dt}[80sin(0.6t)] = 48 cos(0.6t).[/math]
I think I'm OK, on the product rule and chain rule general forms, and I get that 80*0.6 = 48 and that
[math]\frac{d}{dx}[sin(x)] = cos(x)[/math]
but I'm not getting how the whole expression
[math]\frac{d}{dt}[80sin(0.6t)] = 48 cos(0.6t).[/math]
is correct rather than my (incorrect):
[math]\frac{d}{dt}[80sin(0.6t)] = 80 cos(0.6t).[/math]
Clearly, I'm missing an important piece or doing something wrong, but at this point, I'm not getting what that is. Am I missing a simple trig rule or something? Thanks for any insights you might provide.
I was working this Kahn Academy exercise while self-studying differential calculus and boiled my inability to get the right answer down to this piece of product rule (chain rule?) that I wasn't getting somehow:
[math]\frac{d}{dt}[80sin(0.6t)] = 48 cos(0.6t).[/math]
I think I'm OK, on the product rule and chain rule general forms, and I get that 80*0.6 = 48 and that
[math]\frac{d}{dx}[sin(x)] = cos(x)[/math]
but I'm not getting how the whole expression
[math]\frac{d}{dt}[80sin(0.6t)] = 48 cos(0.6t).[/math]
is correct rather than my (incorrect):
[math]\frac{d}{dt}[80sin(0.6t)] = 80 cos(0.6t).[/math]
Clearly, I'm missing an important piece or doing something wrong, but at this point, I'm not getting what that is. Am I missing a simple trig rule or something? Thanks for any insights you might provide.