f(x) = x^2 cos(x)
2006-10-08 11:22:04 · 5 answers · asked by iamthehandcuff 1 in Science & Mathematics ➔ Mathematics
Use the product rule.
f'(x) = (x^2)' (cos x) + (x^2)(cos x)'
You take it from there.
2006-10-08 11:24:00 · answer #1 · answered by MsMath 7 · 0⤊ 0⤋
hope they helped. They are correct. Its the product rule and and then just simple stuff after that. You dont have a composition of functions with the cos(x) so your golden. WEll you kinda do but using the chin rule dy/dx of x is 1 so you would be multiplying by 1.
2006-10-08 18:29:16 · answer #2 · answered by roncho 4 · 0⤊ 0⤋
Start with (uv)' = u'v + uv'
Let u = x^2 Let v=cos(x)
Derivation becomes (2x)*(cos(x)) + (x^2)*(-sin(x))
2x cos(x) - x^2 sin (x) ...negative changed sign
2006-10-08 18:31:10 · answer #3 · answered by highwayman 2 · 0⤊ 0⤋
anytime you have something with an x times something else with an x, you have to use the product rule.
2006-10-08 18:43:41 · answer #4 · answered by Math Geek 2 · 0⤊ 0⤋
Use the product rule:
if h(x)=fg then h'(x)=f'g+g'f, therefore:
your answer is:
2xcos(x)+x^2(-sin(x))
2006-10-08 18:24:31 · answer #5 · answered by mediaptera 4 · 0⤊ 0⤋