Suppose that F(x)=f(g(x)) and g(18)=17,g'(18)=19,f'(18)=14 and f'(17)=5,find F'(18)?I calculated u sing the chain ruleand i came up with 4522,
F(g(x))=f'(g(X)).g'(X)
(14.17)19
4522
did i do it right?
2006-07-09 12:06:19 · 4 answers · asked by lisa 1 in Science & Mathematics ➔ Mathematics
the rule is right, its implementation is wrong
f'(g(x)).g'(x)
= f'(g(18)).g'(18)
=f'(17).g'(18)
=5.19
=95
2006-07-09 12:12:32 · answer #1 · answered by alia_vahed 3 · 1⤊ 0⤋
ok so if u wanted to find F'(18), using chain rule, that is same as finding f'(g(18))*g'(18).
this is equal to 19 * f'(17), which is equal to 19*5 = 95.
so u did it right up till the (14.17)19
f'(g(x)) means u have to find what g(x) is (in this case its 17) and then find f'(x) at that number (so u have to find f'(17)). and then multiply by the 19.
i hope u get that. its kinda hard to explain but ya. laterz
2006-07-09 19:14:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The answer is 95 by using the chain rule and simple substitution
It results in 19 * 5 = 95
2006-07-09 19:31:40 · answer #3 · answered by icehoundxx 6 · 0⤊ 0⤋
Not quite. You have the chain rule correct, but you need to watch out for the values.
F'(18) = [f(g(18))] = f'(g(18)) * g'(18)
= f'(17) * 19
= 5 * 19
F'(18) = 95
The f'(18) isn't need.
2006-07-09 19:14:10 · answer #4 · answered by Ѕємι~Мαđ ŠçїєŋŧιѕТ 6 · 0⤊ 0⤋