Question

Calculate f ′(t). f (t) = (e^(12t)i + 20tj) • (i + 2j) (Note: 12t is a power to e)

Answer 1

looks like the function itself is a dot product of 2 vectors

Answer 2

id try to apply a product rule for vectors :)

Answer 3

Alright, I'll try to see if that works.

Answer 4

f(t) = r(t) l(t)

f'(t) = r(t) l(t)' + r(t)' l(t)

r(t) = <e^(12t),20t>
r(t)'= <12 e^(12t), 20>

l(t) = <1,2>
l(t)'=<0,0>

if im remembering this correctly

Answer 5

http://en.wikipedia.org/wiki/Product_rule#For_vector_functions

Answer 6

f(t)' = <e^(12t),20t> + <12 e^(12t), 20>
< 0 , 0 > < 1 , 2 >
--------------------------------
0+0 + 12e^(12t) + 40

Answer 7

Hey, I was solving it out and I got the same answer as yours, but I did not use your method. I've used the method that my professor gave and that works as well. Thanks for helping me. :)

Answer 8

yep, :) good luck