# Math- calculus

posted by Erin

Given f(x) = x ^ 3 - x ^ 2 -4x +4

Find the zeros of f.

Write an equation of the line tangent to the graph of f at x = -1

The point (a,b) is on the graph of f and the line tangent to the graph at (a,b) passes through the point (0,-8) which is not of the graph of f. Find a and b

1. jazmine

this is my question linda goes to the grocery store every six days,jesus goes to the gorcery store every nine days. they both went to the grocery store today. in how many days will they both be at the grocery store again in the same day i cant solve it could you help me/give me the answer.please

2. Reiny

f(x) = x ^ 3 - x ^ 2 -4x +4
= x^2(x-1) - 4(x-1)
= (x-1)(x^2 - 1)
= (x-1)(x + 2)(x - 2)

so the function has zeros at x = 1,2, -2

f '(x) = 3x^2 - 2x - 4
f '(-1) = 3+2-4 = 1 , which is the slope
f(-1) = 3(-1) - (-1)^2 - 4(-1) + 4
= -3 - 1 + 4 + 4 = 4

so the point is (-1,4) and the slope is 1

can you take it from here?

3. Reiny

Please do not post a new question as a reply to somebody else's question.

re yours ...
Linda goes on day 6, day 12, day 18, day 24 , ....
Jesus goes on day 9, day 18, day 27, ...

mmmmhhhh ?

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