hello all

i'm really happy caz i found a furums that will help me in my homework and this is also quaetions can help me plz/

thax 4 all agian.

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- Nov 4th 2007, 01:48 AMeman.khi want yr sullotions in this questions plz?
hello all

i'm really happy caz i found a furums that will help me in my homework and this is also quaetions can help me plz/

thax 4 all agian. - Nov 4th 2007, 04:34 AMkalagota
i suppose these are calculus questions...

for image003 the function $\displaystyle f(x) = 3 + 4x^3 - x^4$..

a)

$\displaystyle f'(x) = 12x^2 -4x^3$

at x=1, $\displaystyle f'(x)=8$, hence the equation of the tangent line at the point (1,6) is y-6 = 8(x-1) and the equation of the line perpendicular to it is $\displaystyle y-6=\frac{-1}{8}(x-1)$

b) solve for $\displaystyle f'(x) = 0$ and plug in the values of x in f(x) to find their corresponding ordinates..

c) on the interval [-1,2]

f(-1) = -2

f(2) = 19

and f(-1)f(2) = -38 < 0

so, by a corollary to the IVT, there is a c such that f(c) = 0.

indeed, $\displaystyle f(c) = 3 + 4c^3 - c^4 = 0$, solving for c, we have (using a calculating device) -.8519, and 4.0453

Ü